Synthesis of epothilones, intermediates thereto and analogues thereof

ABSTRACT

The present invention provides compounds of formula (I): 
                 
         as described generally and in classes and subclasses herein. The present invention additionally provides pharmaceutical compositions comprising compounds of formula (I) and provides methods of treating cancer comprising administering a compound of formula (I).

PRIORITY INFORMATION

The present application claims priority under 35 U.S.C. § 119(e) to co-pending provisional applications U.S. Ser. No. 60/405,823, filed Aug. 23, 2002, entitled “Synthesis of Epothilones, Intermediates Thereto and Analogues Thereof”; U.S. Ser. No. 60/408,589, filed Sep. 6, 2002, entitled “Synthesis of Epothilones, Intermediates Thereto and Analogues Thereof”; U.S. Ser. No. 60/423,129, filed Nov. 1, 2002, entitled “Synthesis of Epothilones, Intermediates Thereto and Analogues Thereof”, and U.S. Ser. No. 60/456,159, filed Mar. 20, 2003, entitled “Synthesis of Epothilones, Intermediates Thereto and Analogues Thereof”, the entire contents of each of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Epothilones A and B (2a and 2b, Scheme 1) are naturally occurring cytotoxic macrolides that were isolated from a cellulose degrading mycobacterium, Sorangium cellulosum (Höfle et al. Angew. Chem., Int. Ed. Engl. 1996, 35, 1567 and J. Antibiot. 1996, 49, 560; each of which is incorporated herein by reference). Despite their vastly different structures, epothilones A and B share the same mechanism of action as paclitaxel (Taxol®) which involves growth inhibition of tumor cells by tubulin polymerization and stabilization of microtubule assemblies (Bollag et al. Cancer Res. 1995, 55, 2325; incorporated by reference). In spite of its unquestioned clinical value as a front-line chemotherapeutic agent, Taxol® is far from an ideal drug. Its marginal water solubility necessitates recourse to formulation vehicles such as Cremophores that pose their own risks and management issues (Essayan et al. J. Allergy Clin. Immunol. 1996, 97, 42; incorporated herein by reference). Moreover, Taxol® is vulnerable to deactivation through multiple drug resistance (MDR) (Giannakakou et al. J. Biol. Chem. 1997, 272, 17118; incorporated herein by reference). However, it has also been demonstrated that epothilones A and B retain remarkable potency against MDR tumor cells (Kowalski et al. Mol. Biol. Cell 1995, 6, 2137; incorporated herein by reference). Additionally, the increased water solubility in comparison to paclitaxel may be useful for the formulability of epothilones. While the naturally occurring compound, epothilone B (2b, EpoB, in Scheme 1), is a potent member of the epothilone family of natural products, it unfortunately possesses, at least in xenograft mice, a worrisomely narrow therapeutic index (Su et al. Angew. Chem. Int. Ed. Engl. 1997, 36, 1093; Harris et al. J. Org. Chem. 1999, 64, 8434; each of which is incorporated herein by reference).

Given the limited therapeutic index of EpoB, other epothilone analogues, in particular the 12,13-desoxyepothilones, were investigated for their ability to provide an improved therapeutic profile (see, U.S. Pat. Nos. 6,242,469, 6,284,781, 6,300,355, 6,369,234, 6,204,388, 6,316,630; each of which is incorporated herein by reference). In vivo experiments conducted on various mouse models demonstrated that 12,13-desoxyepothilone B (3b, dEpoB in Scheme 2) possesses therapeutic potential against various sensitive and resistant human tumors in mice xenografts (Chou et al. Proc. Natl. Acad. Sci. U.S.A. 1998, 95, 9642 and 15798; incorporated herein by reference). Recently, the therapeutic superiority of these desoxyepothilones over other anticancer agents has been conclusively demonstrated by thorough comparative studies (Chou et al. Proc. Natl. Acad. Sci. U.S.A. 2001, 98, 8113; incorporated herein by reference). Due to its impressive in vivo profile, dEpoB has been advanced through toxicology evaluations in dogs, and is now 2 in human trials as an anticancer drug.

In light of the promising therapeutic utility of the 12,13-desoxyepothilones, it would be desirable to investigate additional analogues as well as additional synthetic methodologies for the synthesis of existing epothilones, desoxyepothilones, and analogues thereof, as well as novel analogues thereof. In particular, given the interest in the therapeutic utility of this class of compounds, it would also be desirable to develop methodologies capable of providing significant quantities of any epothilones or desoxyepothilones previously described, or those described herein, for clinical trials and for large-scale preparation.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table of IC₅₀ values of epothilones against CCRF-CEM cell growth.

FIG. 2 is a ¹H NMR spectrum of trans-9,10-dehydro-12,13-desoxyEpoB.

FIG. 3 is a ¹³C NMR spectrum of trans-9,10-dehydro-12,13-desoxyEpoB.

FIG. 4 shows a scheme for synthesis of 11-R and 14-R epothilones using LACDAC-ring closing olefin methathesis, and illustrates certain substitutions available with synthetic strategies that pass through a 9,10-dehydro epothilone.

FIG. 5 presents relative cytotoxicity data against human leukemic cells in vitro for a variety of epothilone compounds and derivatives including certain 9,10-dehydro compounds (e.g., compound 7 in FIG. 5A and compound 89 in FIG. 5B).

FIG. 6 depicts alternative synthetic strategies for preparing 9,10-dehydro epothilone analogs.

FIG. 7 shows analogs of 9,10-dehydro-12,13-desoxy EpoB.

FIG. 8 shows the therapeutic effect of 9,10-dehydro-dEpoB and dEpoB in nude mice bearing human mammary carcinoma MX-1 xenograft.

FIG. 9 shows the stability of epothilone analogs in murine plasma. Epo 1 is 12,13-desoxyEpoB, Epo 2 is 26-F₃-12,13-desoxyEpoB, Epo 3 is (E)-9,10-dehydro-12,13-desoxyEpoB, and Epo 4 is 26-F₃-(E)-9,10-dehydro-12,13-desoxyEpoB.

FIG. 10 depicts the therapeutic effect of epothilone analogs in nude mice bearing HCT-116 xenograft (iv infusion, Q2Dx7, n=3). Arrows indicate drug administration.

FIG. 11 shows the potencies of various epothilone analogues against tumor cell growth in vitro and therapeutic index, as compared to paclitaxel and vinblastine.

FIG. 12 is a table summarizing the effect of dEpoB, Taxol, and 26-triF-9,10-deH-dEpoB against MX-1 xenograft in nude mice.

FIG. 13 shows the effect of 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-EpoB on tumor size in nude mice bearing MX-1 xenografts.

FIG. 14 shows body weight changes of nude mice bearing human mammary carcinoma tumor MX-1 xenograft following treatment with 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-EpoB.

FIG. 15 shows the therapeutic effect of 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydroEpoB on tumor size in nude mice bearing MX-1 xenografts.

FIG. 16 shows body weight changes of nude mice bearing human mammary carcinoma tumor MX-1 xenograft following treatment with 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-EpoB.

FIG. 17 shows the effect of 9,10-dehydro-dEpoB on tumor size in nude mice bearing HCT-116 xenografts.

FIG. 18 shows the effect of 9,10-dehydro-dEpoB on tumor size in nude mice bearing human colon carcinoma HCT-116 xenografts.

FIG. 19 shows the effect of 9,10-dehydro-dEpoB on tumor size in nude mice bearing A549/Taxol xenografts.

FIG. 20 shows changes in body weight of nude mice bearing A549/Taxol xenograft treated with 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-dEpoB.

FIG. 21 shows the effect of 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-dEpoB on tumor size in nude mice bearing A549/Taxol xenografts.

FIG. 22 shows changes in body weight of nude mice bearing A549/Taxol xenografts treated with 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-dEpoB.

FIG. 23 shows the effect of 9,10-dehydro-EpoB on tumor size in nude mice bearing human colon carcinoma HCT-116 tumor xenografts.

FIG. 24 shows changes in body weight of nude mice bearing human colon carcinoma HCT-116 tumor xenograft following treatment with 9,10-dehydro-EpoB.

FIG. 25 shows microtubule formation from tubulin in the presence of various epothilone analogues at 37° C.

FIG. 26 shows microtubule formation from tubulin in the presence of various epothilone analogues at 4° C.

FIG. 27 shows the effect of 9,10-dehydro-dEpoB and dEpoB on tumor size in nude mice bearing HCT-116 xenografts.

FIG. 28 shows changes in body weight of nude mice bearing HCT-116 xenografts after treatment with 9,10-dehydro-dEpoB and dEpoB.

FIG. 29 shows the effect of 9,10-dehydro-dEpoB on tumor size in nude mice bearing human colon carcinoma HCT-116 xenografts.

FIG. 30 shows changes in body weight of nude mice bearing human colon carcinoma tumor HCT-116 xenografts following treatment with 9,10-dehydro-dEpoB (5 mg/kg, iv infusion, X3Dx4).

FIG. 31 is table with IC50 values for epothilone analogues against CCRF-CEM cell growth.

FIG. 32 shows the metabolic stability of epothione analogues in vitro and in vivo.

FIG. 33 is table detailing the therapeutic effects of various epothilone analogues against human tumor xenografts in mice with 6 hour iv infusion.

FIG. 34 shows the effect of 9,10-dehydro-EpoB and oxazole-EpoD on tumor size in nude mice bearing human colon carcinoma HCT-116 tumor xenograft (6 hour iv infusion, Q2Dx7).

FIG. 35 shows changes in body weight of nude mice bearing human colon carcinoma HCT-116 tumor xenografts following treatment with 9,10-dehydro-EpoB and oxazole-EpoD (6 hour infusion, Q2Dx7).

FIG. 36 shows the effect of 26-trifluoro-9,10-dehydro-dEpoB and 9,10-dehydro-dEpoB on tumor size in nude mice bearing A549/Taxol xenografts (6 hour iv infusion, Q2Dx4).

FIG. 37 shows the effect of 9,10-dehydro-dEpoB on tumor size in nude mice bearing A549/Taxol xenografts (6 hour iv infusion, Q3Dx3).

FIG. 38 shows the stability of epothilone analogues in 20% mouse plasma/PBS.

FIG. 39 shows the stability of epothilone analogues in 10% Men Liver S9/PBS.

FIG. 40 shows EpoD stability chromatogram in 10% Men Liver S9/PBS.

FIG. 41 are tables describing the effect of various epothilone analogues on in vitro microtubule polymerization at 37° C. in the absence of GTP (A) and the cytotoxicity of various epothilone analogs in the human lung cell line A549 (B).

FIG. 42 shows the stabilization of microtubule formation by epothilones at 35° C. and 4° C.

FIG. 43 shows the therapeutic effect of 9,10-dehydro-dEpoB in nude mice bearing T human mammary carcinoma (MX-1) xenograft (6 hour infusion, Q2Dx5).

FIG. 44 shows the change in body weight of nude mice bearing human mammary carcinoma (MX-1) xenograft following treatment with 9,10-dehydro-dEpoB (6 hour infusion, Q2Dx8, n=4).

FIG. 45 shows the change in body weight of nude mice bearing HCT-116 xenograft following treatment with 9,10-dehydro-dEpoB (iv infusion, Q2Dx7).

FIG. 46 shows the therapeutic effect of 9,10-dehydro-dEpoF, dEpoB, and Taxol on tumor size in nude mice bearing human mammary carcinoma (MX-1) tumor xenograft (6 hour iv infusion, Q2Dx6).

FIG. 47 shows the changes in body weight of nude mice bearing human mammary carcinoma (MX-1) tumor xenograft following treatment with 9,10-dehydro-dEpoF, dEpoB, and Taxol (6 hour infusion, Q2Dx6).

FIG. 48 shows the therapeutic effect of 9,10-dehydo-dEpoF and dEpoB in nude mice bearing human colon carcinoma HCT-116 xenograft (6 hour infusion, Q2Dx8).

FIG. 49 shows the changes in body weight of nude mice bearing HCT-116 xenograft following treatment with 9,10-dehydro-dEpoF and dEpoB (6 hour infusion, Q2Dx8).

FIG. 50 shows the therapeutic effect of 9,10-dehydro-dEpoF and dEpoB in nude mice bearing Taxol-resistant human lung carcinoma (A549/Taxol) xenograft (6 hour infusion, Q2Dx5).

FIG. 51 shows changes in body weight of nude mice bearing Taxol-resistant human lung carcinoma (A549/Taxol) xenograft following treatment with 9,10-dehydro-dEpoF and dEpoB (6 hour infusion, Q2Dx5).

DEFINITIONS

Certain compounds of the present invention, and definitions of specific functional groups are also described in more detail below. For purposes of this invention, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75^(th) Ed., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and reactivity, are described in “Organic Chemistry”, Thomas Sorrell, University Science Books, Sausalito: 1999, the entire contents of which are incorporated herein by reference. Furthermore, it will be appreciated by one of ordinary skill in the art that the synthetic methods, as described herein, utilize a variety of protecting groups. By the term “protecting group”, as used herein, it is meant that a particular functional moiety, e.g., O, S, or N, is temporarily blocked so that a reaction can be carried out selectively at another reactive site in a multifunctional compound. In preferred embodiments, a protecting group reacts selectively in good yield to give a protected substrate that is stable to the projected reactions; the protecting group must be selectively removed in good yield by readily available, preferably nontoxic reagents that do not attack the other funcational groups; the protecting group forms an easily separable derivative (more preferably without the generation of new stereogenic centers); and the protecting group has a minimum of additional functionality to avoid further sites of reaction. As detailed herein, oxygen, sulfur, nitrogen and carbon protecting groups may be utilized. Exemplary protecting groups are detailed herein, however, it will be appreciated that the present invention is not intended to be limited to these protecting groups; rather, a variety of additional equivalent protecting groups can be readily identified using the above criteria and utilized in the method of the present invention. Additionally, a variety of protecting groups are described in “Protective Groups in Organic Synthesis” Third Ed. Greene, T. W. and Wuts, P. G., Eds., John Wiley & Sons, New York: 1999, the entire contents of which are hereby incorporated by reference.

It will be appreciated that the compounds, as described herein, may be substituted with any number of substituents or functional moieties. In general, the term “substituted” whether preceded by the term “optionally” or not, and substituents contained in formulas of this invention, refer to the replacement of hydrogen radicals in a given structure with the radical of a specified substituent. When more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at every position. As used herein, the term “substituted” is contemplated to include all permissible substituents of organic compounds. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. For purposes of this invention, heteroatoms such as nitrogen may have hydrogen substituents and/or any permissible substituents of organic compounds described herein which satisfy the valencies of the heteroatoms. Furthermore, this invention is not intended to be limited in any manner by the permissible substituents of organic compounds. Combinations of substituents and variables envisioned by this invention are preferably those that result in the formation of stable compounds useful in the treatment, for example of proliferative disorders, including, but not limited to cancer. The term “stable”, as used herein, preferably refers to compounds which possess stability sufficient to allow manufacture and which maintain the integrity of the compound for a sufficient period of time to be detected and preferably for a sufficient period of time to be useful for the purposes detailed herein.

The term “aliphatic”, as used herein, includes both saturated and unsaturated, straight chain (i.e., unbranched), branched, cyclic, or polycyclic aliphatic hydrocarbons, which are optionally substituted with one or more functional groups. As will be appreciated by one of ordinary skill in the art, “aliphatic” is intended herein to include, but is not limited to, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and cycloalkynyl moieties. Thus, as used herein, the term “alkyl” includes straight, branched and cyclic alkyl groups. An analogous convention applies to other generic terms such as “alkenyl”, “alkynyl” and the like. Furthermore, as used herein, the terms “alkyl”, “alkenyl”, “alkynyl” and the like encompass both substituted and unsubstituted groups. In certain embodiments, as used herein, “lower alkyl” is used to indicate those alkyl groups (cyclic, acyclic, substituted, unsubstituted, branched or unbranched) having 1-6 carbon atoms.

In certain embodiments, the alkyl, alkenyl and alkynyl groups employed in the invention contain 1-20 aliphatic carbon atoms. In certain other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-10 aliphatic carbon atoms. In yet other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-8 aliphatic carbon atoms. In still other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-6 aliphatic carbon atoms. In yet other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-4 carbon atoms. Illustrative aliphatic groups thus include, but are not limited to, for example, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, —CH₂-cyclopropyl, allyl, n-butyl, sec-butyl, isobutyl, tert-butyl, cyclobutyl, —CH₂-cyclobutyl, n-pentyl, sec-pentyl, isopentyl, tert-pentyl, cyclopentyl, —CH₂-cyclopentyl, n-hexyl, sec-hexyl, cyclohexyl, —CH₂-cyclohexyl moieties and the like, which again, may bear one or more substituents. Alkenyl groups include, but are not limited to, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl, and the like. Representative alkynyl groups include, but are not limited to, ethynyl, 2-propynyl (propargyl), 1-propynyl and the like.

The term “alkoxy”, or “thioalkyl” as used herein refers to an alkyl group, as previously defined, attached to the parent molecular moiety through an oxygen atom or through a sulfur atom. In certain embodiments, the alkyl group contains 1-20 alipahtic carbon atoms. In certain other embodiments, the alkyl group contains 1-10 aliphatic carbon atoms. In yet other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-8 aliphatic carbon atoms. In still other embodiments, the alkyl group contains 1-6 aliphatic carbon atoms. In yet other embodiments, the alkyl group contains 1-4 aliphatic carbon atoms. Examples of alkoxy, include but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, tert-butoxy, neopentoxy and n-hexoxy. Examples of thioalkyl include, but are not limited to, methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, and the like.

The term “alkylamino” refers to a group having the structure —NHR′ wherein R′ is alkyl, as defined herein. In certain embodiments, the alkyl group contains 1-20 aliphatic carbon atoms. In certain other embodiments, the alkyl group contains 1-10 aliphatic carbon atoms. In yet other embodiments, the alkyl, alkenyl, and alkynyl groups employed in the invention contain 1-8 aliphatic carbon atoms. In still other embodiments, the alkyl group contains 1-6 aliphatic carbon atoms. In yet other embodiments, the alkyl group contains 1-4 aliphatic carbon atoms. Examples of alkylamino include, but are not limited to, methylamino, ethylamino, iso-propylamino and the like.

Some examples of substituents of the above-described aliphatic (and other) moieties of compounds of the invention include, but are not limited to aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl; heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; F; Cl; Br; I; —OH; —NO₂; —CN; —CF₃; —CH₂CF₃; —CHCl₂; —CH₂OH; —CH₂CH₂OH; —CH₂NH₂; —CH₂SO₂CH₃; —C(O)R_(x); —CO₂(R_(x)); —OC(O)R_(x); —OCO₂R_(x); —OCON(R_(x))₂; —N(R_(x))₂; —S(O)₂R_(x); —NR_(x)(CO)R_(x) wherein each ocurrence of R_(x) independently includes, but is not limited to, aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic, arylalkyl, or heteroarylalkyl substituents described above and herein may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and wherein any of the aryl or heteroaryl substituents described above and herein may be substituted or unsubstituted. Additional examples of generally applicable substituents are illustrated by the specific embodiments shown in the Examples that are described herein.

In general, the terms “aryl” and “heteroaryl”, as used herein, refer to stable mono- or polycyclic, heterocyclic, polycyclic, and polyheterocyclic unsaturated moieties having preferably 3-14 carbon atoms, each of which may be substituted or unsubstituted. Substituents include, but are not limited to, any of the previously mentioned substitutents, i.e., the substituents recited for aliphatic moieties, or for other moieties as disclosed herein, resulting in the formation of a stable compound. In certain embodiments of the present invention, “aryl” refers to a mono- or bicyclic carbocyclic ring system having one or two aromatic rings including, but not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, indenyl and the like. In certain embodiments of the present invention, the term “heteroaryl”, as used herein, refers to a cyclic aromatic radical having from five to ten ring atoms of which one ring atom is selected from S, O and N; zero, one or two ring atoms are additional heteroatoms independently selected from S, O and N; and the remaining ring atoms are carbon, the radical being joined to the rest of the molecule via any of the ring atoms, such as, for example, pyridyl, pyrazinyl, pyrimidinyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isooxazolyl, thiadiazolyl, oxadiazolyl, thiophenyl, furanyl, quinolinyl, isoquinolinyl, and the like.

It will be appreciated that aryl and heteroaryl groups (including bicyclic aryl groups) can be unsubstituted or substituted, wherein substitution includes replacement of one, two or three of the hydrogen atoms thereon independently with any one or more of the following moieties including, but not limited to: aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl; heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; F; Cl; Br; I; —OH; —NO₂; —CN; —CF₃; —CH₂CF₃; —CHCl₂; —CH₂OH; —CH₂CH₂OH; —CH₂NH₂; —CH₂SO₂CH₃; —C(O)R_(x); —CO₂(R_(x)); —CON(R_(x)) ₂; —OCO₂R_(x); —OCON(R_(x))₂; —N(R_(x))₂; —S(O)₂R_(x); —NR_(x)(CO)R_(x) wherein each occurrence of R_(x) independently includes, but is not limited to, aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic, arylalkyl, or heteroarylalkyl substituents described above and herein may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and wherein any of the aryl or heteroaryl substituents described above and herein may be substituted or unsubstituted. Additional examples of generally applicable substitutents are illustrated by the specific embodiments shown in the Examples that are described herein.

The term “cycloalkyl”, as used herein, refers specifically to groups having three to seven, preferably three to ten carbon atoms. Suitable cycloalkyls include, but are not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like, which, as in the case of other aliphatic, heteroaliphatic or hetercyclic moieties, may optionally be substituted with substituents including, but not limited to aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl; heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; F; Cl; Br; I; —OH; —NO₂; —CN; —CF₃; —CH₂CF₃; —CHCl₂; —CH₂OH; —CH₂CH₂OH; —CH₂NH₂; —CH₂SO₂CH₃; —C(O)R_(x); —CO₂(R_(x)); —CON(R_(x))₂; —OC(O)R_(x); —OCO₂R_(x); —OCON(R_(x))₂; —N(R_(x))₂; —S(O)₂R_(x); —NR_(x)(CO)R_(x) wherein each occurrence of R_(x) independently includes, but is not limited to, aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic, arylalkyl, or heteroarylalkyl substituents described above and herein may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and wherein any of the aryl or heteroaryl substituents described above and herein may be substituted or unsubstituted. Additional examples of generally applicable substitutents are illustrated by the specific embodiments shown in the Examples that are described herein.

The term “heteroaliphatic”, as used herein, refers to aliphatic moieties that contain one or more oxygen, sulfur, nitrogen, phosphorus or silicon atoms, e.g., in place of carbon atoms. Heteroaliphatic moieties may be branched, unbranched, cyclic or acyclic and include saturated and unsaturated heterocycles such as morpholino, pyrrolidinyl, etc. In certain embodiments, heteroaliphatic moieties are substituted by independent replacement of one or more of the hydrogen atoms thereon with one or more moieties including, but not limited to aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl; heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; F; Cl; Br; I; —OH; —NO₂; —CN; —CF₃; —CH₂CF₃; —CHCl₂; —CH₂OH; —CH₂CH₂OH; —CH₂NH₂; —CH₂SO₂CH₃; —C(O)R_(x); —CO₂(R_(x)); —CON(R_(x))₂; —OC(O)R_(x); —OCO₂R_(x); —OCON(R_(x))₂; —N(R_(x))₂; —S(O)₂R_(x); —NR_(x)(CO)R_(x) wherein each occurrence of R_(x) independently includes, but is not limited to, aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic, arylalkyl, or heteroarylalkyl substituents described above and herein may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and wherein any of the aryl or heteroaryl substituents described above and herein may be substituted or unsubstituted. Additional examples of generally applicable substitutents are illustrated by the specific embodiments shown in the Examples that are described herein.

The terms “halo” and “halogen” as used herein refer to an atom selected from fluorine, chlorine, bromine and iodine.

The term “haloalkyl” denotes an alkyl group, as defined above, having one, two, or three halogen atoms attached thereto and is exemplified by such groups as chloromethyl, bromoethyl, trifluoromethyl, and the like.

The term “heterocycloalkyl” or “heterocycle”, as used herein, refers to a non-aromatic 5-, 6- or 7-membered ring or a polycyclic group, including, but not limited to a bi- or tricyclic group comprising fused six-membered rings having between one and three heteroatoms independently selected from oxygen, sulfur and nitrogen, wherein (i) each 5-membered ring has 0 to 1 double bonds and each 6-membered ring has 0 to 2 double bonds, (ii) the nitrogen and sulfur heteroatoms may be optionally be oxidized, (iii) the nitrogen heteroatom may optionally be quaternized, and (iv) any of the above heterocyclic rings may be fused to a benzene ring. Representative heterocycles include, but are not limited to, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl, oxazolidinyl, isoxazolidinyl, morpholinyl, thiazolidinyl, isothiazolidinyl, and tetrahydrofuryl. In certain embodiments, a “substituted heterocycloalkyl or heterocycle” group is utilized and as used herein, refers to a heterocycloalkyl or heterocycle group, as defined above, substituted by the independent replacement of one, two or three of the hydrogen atoms thereon with but are not limited to aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl; heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy; alkylthio; arylthio; heteroalkylthio; heteroarylthio; F; Cl; Br; I; —OH; —NO₂; —CN; —CF₃; —CH₂CF₃; —CHCl₂; —CH₂OH; —CH₂CH₂OH; —CH₂NH₂; —CH₂SO₂CH₃; —C(O)R_(x); —CO₂(R_(x)); —CON(R_(x))₂; —OC(O)R_(x); —OCO₂R_(x); —OCON(R_(x))₂; —S(O)₂R_(x); —NR_(x)(CO)R_(x) wherein each occurence of R_(x) independently includes, but is not limited to, aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic, arylalkyl, or heteroarylalkyl substituents described above and herein may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and wherein any of the aryl or heteroaryl substituents described above and herein may be substituted or unsubstituted. Additional examples of generally applicable substitutents are illustrated by the specific embodiments shown in the Examples which are described herein.

“Labeled”: As used herein, the term “labeled” is intended to mean that a compound has at least one element, isotope or chemical compound attached to enable the detection of the compound. In general, labels fall into three classes: a) isotopic labels, which may be radioactive or heavy isotopes, including, but not limited to, ²H, ³H, ³²p, ³⁵S, ⁶⁷Ga, ^(99m)Tc (Tc-99m), ¹¹¹ln, ¹²³I, ¹²⁵I, ¹⁶⁹Yb and ¹⁸⁶Re; b) immune labels, which may be antibodies or antigens; and c) colored or fluorescent dyes. It will be appreciated that the labels may be incorporated into the compound at any position that does not interfere with the biological activity or characteristic of the compound that is being detected. In certain embodiments of the invention, photoaffinity labeling is utilized for the direct elucidation of intermolecular interactions in biological systems (e.g., to probe the epothilone binding site in a tubulin dimer). A variety of known photophores can be employed, most relying on photoconversion of diazo compounds, azides, or diazirines to nitrenes or carbenes (See, Bayley, H., Photogenerated Reagents in Biochemistry and Molecular Biology (1983), Elsevier, Amsterdam.), the entire contents of which are hereby incorporated by reference. In certain embodiments of the invention, the photoaffinity labels employed are o-, m- and p-azidobenzoyls, substituted with one or more halogen moieties, including, but not limited to 4-azido-2,3,5,6-tetrafluorobenzoic acid.

“Polymer”: The term “polymer”, as used herein, refers to a composition comprising chains that may be open, closed, linear, branched or cross-linked of repeating units (monomers) that may be the same or different. It will be appreciated that in certain embodiments the term polymer refers to biopolymers, which, as used herein, is intended to refer to polymeric materials found in nature or based upon those materials found in nature, including, but not limited to nucleic acids, peptides, and mimetics thereof. In certain other embodiments, the term polymer refers to synthetic polymers, such as biodegradable polymers or other polymeric materials. It will be appreciated that polymeric solid supports are also encompassed by the polymers of the present invention. Inventive compounds can be attached to polymeric supports and thus certain synthetic modifications can be conducted on the solid phase. As used herein, the term “solid support” is meant to include, but is not limited to, pellets, disks, capillaries, hollow fibers, needles, pins, solid fibers, cellulose beads, pore-glass beads, silica gels, polystyrene beads optionally cross-linked with divinylbenzene, grafted co-poly beads, poly-acrylamide beads, latex beads, dimethylacrylamide beads optionally crosslinked with N-N′-bis-acryloylethylenediamine, and glass particles coated with a hydrophobic polymer. One of ordinary skill in the art will realize that the choice of particular solid support will be limited by the compatability of the support with the reaction chemistry being utilized. An exemplary solid support is a Tentagel amino resin, a composite of 1) a polystyrene bead crosslinked with divinylbenzene and 2) PEG (polyethylene glycol). Tentagel is a particularly useful solid support because it provides a versatile support for use in on-bead or off-bead assays, and it also undergoes excellent swelling in solvents ranging from toluene to water.

DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

In recognition of the need to develop novel and effective cancer therapies, the present invention provides novel synthetic methodologies enabling access to macrocycles having a broad range of biological and pharmacological activity, as well as novel compounds with such activity, novel therapeutic compositions, and methods of using these compounds and compositions.

In certain embodiments, the inventive compounds are useful in the treatment of cancer. Certain compounds of the invention exhibit cytotoxic or growth inhibitory effects on cancer cells lines, exhibit an ability to polymerize tubulin and stabilize microtubule assemblies, and/or lead to shrinkage or diappearance of tumors in cancer cell xenograft models. In certain embodiments, the compounds-may have reduced or minimal side effects including toxicity to vital organs, nausea, vomiting, diarrhea, allopecia, weight loss, weight gain, liver toxicity, skin disorders, etc. The compounds may also be easier to formulate due to increased water solubility, decreased toxicity, increased therapeutic range, increased efficacy, etc.

General Description of Compounds of the Invention

Compounds of the invention include compounds of the general formula (0) and (0′) as further defined below:

-   -   wherein R₀ is a substituted or unsubstituted aryl, heteroaryl,         arylalkyl, arylalkenyl, arylalkynyl, heteroarylalkyl,         heteroarylalkenyl, or heteroarylalkynyl moiety; in certain         embodiments, R₀ is a arylalkyl, arylalkenyl, heteroarylalkyl, or         heteroarylalkenyl moiety; in other embodiments, R₀ is a         heteroarylalkenyl moiety; in certain embodiments, R₀ is a         heteroarylalkyl moiety; in other embodiments, R₀ is a 5-7         membered aryl or heteroaryl moiety; in yet other embodiments, R₀         is an 8-12 membered bicyclic aryl or heteroaryl moiety; in still         other embodiments, R₀ is a bicyclic moiety wherein a phenyl ring         is fused to a heteroaryl or aryl moiety; in other embodiments,         R₀ is a bicyclic moiety wherein a phenyl ring is fused to a         thiazole, oxazole, or imidazole moiety; in yet other         embodiments, R₀ is a substituted or unsubstituted phenyl moiety;     -   R₃ and R₄ are each independently hydrogen; or substituted or         unsubstituted, linear or branched, cyclic or acyclic aliphatic,         heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl         moiety, optionally substituted by one or more of hydroxy,         protected hydroxy, alkoxy, carboxy, carboxaldehyde, linear or         branched alkyl or cyclic acetal, fluorine, amino, protected         amino, amino substituted with one or two alkyl or aryl moieties,         N-hydroximino, or N-alkoxyimino; in certain embodiments, R₃ and         R₄ are each independently hydrogen, fluorine, or lower alkyl; in         other embodiments, R₃ and R₄ are each independently hydrogen or         methyl; in still other embodiments, R₃ is methyl, and R₄ is         hydrogen;     -   R₅ and R₆ are each independently hydrogen or a protecting group;         in certain embodiments, R₅ and R₆ are both hydrogen;     -   X is O, S, C(R₇)₂, or NR₇, wherein each occurrence of R₇ is         independently hydrogen or lower alkyl; in certain embodiments, X         is O; in other embodiments, X is NH;     -   Y is O, S, NH, C(R₇)₂, CH₂, N(R₇), or NH, wherein each         occurrence of R₇ is independently hydrogen or lower alkyl; in         certain embodiments, Y is O; in other embodiments, Y is NH; in         yet other embodiments, Y is CH₂;     -   each R₈ is independently hydrogen; halogen, hydroxy, alkoxy,         amino, dialkylamino, alkylamino, fluoro, cyano, or substituted         or unsubstituted, linear or branched, cyclic or acyclic         aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl,         arylalkenyl, arylalkynyl, or heteroarylalkyl, heteroarylalkenyl,         heteroarylalkynyl moiety, optionally substituted by one or more         of hydroxy, protected hydroxy, alkoxy, carboxy, caboxaldehyde,         linear or branched alkyl or cyclic acetal, fluorine, amino,         protected amino, amino substituted with one or two alkyl or aryl         moieties, N-hydroximino, or N-alkoxyimino; in certain         embodiments, R₈ is hydrogen; in other embodiments, R₈ is         hydroxy; in yet other embodiments, R₈ is fluorine; in still         other embodiments, R₈ is lower alkyl such as methyl; in other         embodiments R₈ is —CF₃, —CF₂H, or —CFH₂; in other embodiments,         R₈ is perfluorinated or fluorinated alkyl group; in yet other         embodiments, R₈ is halogentated or perhalogenated alkyl group;     -   R₉ and R₁₀ are each indenpendently hydrogen; or substituted or         unsubstituted, linear or branched, cyclic or acyclic aliphatic,         heteroaliphatic, aryl, heteroaryl, aryl, arylalkyl, arylalkenyl,         arylalkynyl, heteroarylalkyl, heteroarylalkenyl, or         heteroarylalkynyl moiety, optionally substituted by one or more         of hydroxy, protected hydroxy, alkoxy, carboxy, carboxaldehyde,         linear or branched alkyl or cyclic acetal, fluorine, amino,         protected amino, amino substituted with one or two alkyl or aryl         moieties, N-hydroximino, or N-alkoxyimino; in certain         embodiments, one of R₉ and R₁₀ is methyl; in other embodiments,         both R₉ and R₁₀ are methyl; in yet other embodiments, one of R₉         and R₁₀ is methyl, and the other is hydrogen; in other         embodiments, both R₉ and R₁₀ are hydrogen;     -   R_(B) is, independently for each occurrence, hydrogen; halogen;         —OR_(B′); —SR_(B′); —N(R_(B′))₂; —C(O)OR_(B′); —C(O)R_(B′);         —CONHR_(B′); —O(C═O)R_(B′); —O(C═O)OR_(B′); —NR_(B′)(C=O)R_(B′);         N₃; N₂R_(B′); cyclic acetal; or cyclic or acyclic, linear or         branched aliphatic, heteroaliphatic, aryl, or heteroaryl,         optionally substituted with one or more of hydrogen; halogen;         —OR_(B′); —SR_(B′); —N(R_(B′))₂; —C(O)OR_(B′); —C(O)R_(B′);         —CONHR_(B′); —O(C═O)R_(B′); —O(C═O)OR_(B′);         —NR_(B′)(C═O)R_(B′)(C═O)R_(B′); N₃; —N₂R_(B′); cyclic acetal; or         cyclic or acyclic, linear or branched substituted or         unsubstituted aliphatic, heteroaliphatic, aryl, or heteroaryl         moiety; or is an epothilone, desoxyepothilone, or analogues         thereof; or is a polymer; carbohydrate; photoaffinity label; or         radiolabel; in certain embodiments, R_(B) is hydrogen,     -    methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl,         cyclobutyl, cyclopentyl, or cyclohexyl, each unsubstituted or         optionally substituted with one or more occurrences of halogen,         —OH, —OR_(B′), NH₂, or N(R_(B′))₂, or any combination thereof,         wherein each occurrence of R_(B′) is independently hydrogen,         alkyl, aryl, or a protecting group, in other embodiments, R_(B)         is hydrogen, methyl, or ethyl, in still other embodiments, R_(B)         is methyl, in other embodiments, —CY₃, —CHY₂, —CH₂Y, where Y is         F, Br, Cl, I, OR_(B′), NHR_(B′), N(R_(B′))₂, or SR_(B′); in yet         other embodiments, R_(B) is —CF₃, —CH₂F, or CHF₂; in other         embodiments, R_(B) is perfluorinated or fluorinated alkyl group;         in yet other embodiments, R_(B) is halogentated or         perhalogenated alkyl group;     -   each occurrence of R_(B′) is independently hydrogen; a         protecting group; a linear or branched, substituted or         unsubstituted, cyclic or acyclic, aliphatic, heteroalliphatic,         aryl, heteroaryl, arylalkyl, arylalkenyl, arylalkynyl,         heteroarylalkyl, heteroarylalkenyl, or heteroarylalkynyl moiety;     -   m is 1, 2, 3, or 4, m is 1 or 2 in certain embodiments, m is 1         in other embodiments; and pharmaceutically acceptable         derivatives thereof.

The compounds of the invention include compounds of the general formula (I) or (I′) as further defined below:

-   -   wherein R₁ is hydrogen or lower alkyl; in certain embodiments,         R₁ is methyl; in certain embodiments, R₁ is —CF₃, —CF₂H, or         CH₂F; in other embodiments, R₁ is perfluorinated or fluorinated         alkyl group; in yet other embodiments, R₁ is halogentated or         perhalogenated alkyl group;     -   R₂ is a substituted or unsubstituted aryl, heteroaryl,         arylalkyl, or heteroarylalkyl moiety; in certain embodiments, R₂         is substituted or unsubstituted oxazole; in other embodiments,         R₂ is substituted or unsubstituted thiazole;     -   R₃ and R₄ are each independently hydrogen; or substituted or         unsubstituted, linear or branched, cyclic or acyclic aliphatic,         heteroaliphatic, aryl, heteroaryl, arylalkyl, or heteroarylalkyl         moiety, optionally substituted by one or more of hydroxy,         protected hydroxy, alkoxy, carboxy, carboxaldehyde, linear or         branched alkyl or cyclic acetal, fluorine, amino, protected         amino, amino substituted with one or two alkyl or aryl moieties,         N-hydroximino, or N-alkoxyimino; in certain embodiments, R₃ and         R₄ are each independently hydrogen, fluorine, or lower alkyl; in         other embodiments, R₃ and R₄ are each independently hydrogen or         methyl; in still other embodiments, R₃ is methyl, and R₄ is         hydrogen;     -   R₅ and R₆ are each independently hydrogen or a protecting group;         in certain embodiments, R₅ and R₆ are both hydrogen;     -   X is O, S, C(R₇)₂, or NR₇, wherein each occurrence of R₇ is         independently hydrogen or lower alkyl; in certain embodiments, X         is O; in other embodiments, X is NH;     -   R_(B) is, independently for each occurrence, hydrogen; halogen;         —OR_(B′); —SR_(B′); —N(R_(B′))₂; —C(O)OR_(B′); —C(O)R_(B′);         —CONHR_(B′); —O(C═O)R_(B′); —O(C═O)OR_(B′); —NR_(B′)(C═O)R_(B′);         N₃; N₂R_(B′); cyclic acetal; or cyclic or acyclic, linear or         branched aliphatic, heteroaliphatic, aryl, or heteroaryl,         optionally substituted with one or more of hydrogen; halogen;         —OR_(B′); —SR_(B′); —N(R_(B′))₂; —C(O)OR_(B′); —C(O)R_(B′);         —CONHR_(B′); —O(C═O)R_(B′); —O(C═O)OR_(B′); —NR_(B′)(C═O)R_(B′);         N₃; N₂R_(B′); cyclic acetal; or cyclic or acyclic, linear or         branched substituted or unsubstituted aliphatic,         heteroaliphatic, aryl, or heteroaryl moiety; or is an         epothilone, desoxyepothilone, or analogues thereof; or is a         polymer; carbohydrate; photoaffinity label; or radiolabel; in         certain embodiments, R_(B) is hydrogen,     -    methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopropyl,         cyclobutyl, cyclopentyl, or cyclohexyl, each unsubstituted or         optionally substituted with one or more occurrences of halogen,         —OH, —OR_(B′), NH₂, or N(R_(B′))₂, or any combination thereof,         wherein each occurrence of R_(B′) is independently hydrogen,         alkyl, aryl, or a protecting group, in other embodiments, R_(B)         is hydrogen, methyl, or ethyl, in still other embodiments, R_(B)         is methyl, in yet other embodiments, R_(B) is —CF₃, —CH₂F, or         CHF₂; and pharmaceutically acceptable derivatives thereof.

In certain embodiments, the compounds of the invention include compounds of the general formula (II) or (II′) with the stereochemistry defined as shown:

wherein X, R₁, R₂, R₃, R₄, R₅, R₆, R_(B), and X are as defined above.

In certain embodiments, X is O. In other embodiments, X is NH. In other embodiments, X is CH₂.

In some embodiments, R₂ is a substituted or unsubstituted thiazole. In certain embodiments, R₂ is 2-methyl-thiazo-4-yl. In other embodiments, R₂ is 2-hydroxylmethyl-thiazo-4-yl. In yet other embodiments, R₂ is 2-aminomethyl-thiazo-4-yl. In other embodiments, R₂ is 2-thiolmethyl-thiazo-4-yl.

In certain embodiments R₂ is a substituted or unsubstituted oxazole. In certain embodiments, R₂ is 2-methyl-oxazo-4-yl. In other embodiments, R₂ is 2-hydroxylmethyl-oxazo-4-yl. In yet other embodiments, R₂ is 2-aminomethyl-oxazo-4-yl. In other embodiments, R₂ is 2-thiolmethyl-oxazo-4-yl.

In certain embodiments, R_(B) is hydrogen, methyl, ethyl, —CF₃, —CH₂F, —CF₂H. In certain embodiments, R_(B) is methyl. In yet other embodiments, R_(B) is —CF₃. In certain embodiments, R_(B) is hydrogen. In other embodiments, R_(B) is ethyl.

Certain preferred compounds include, for example:

Compounds of this invention include those specifically set forth above and described herein, and are illustrated in part by the various classes, subgenera and species disclosed elsewhere herein.

It will be appreciated by one of ordinary skill in the art that asymmetric centers may exist in the compounds of the present invention. Thus, inventive compounds and pharmaceutical compositions thereof may be in the form of an individual enantiomer, diastereomer or geometric isomer, or may be in the form of a mixture of stereoisomers. In certain embodiments, the compounds of the invention are enantiopure compounds. In certain other embodiments, a mixtures of stereoisomers or diastereomers are provided.

It will be appreciated that some of the foregoing classes and subclasses of compounds can exist in various isomeric forms. The invention encompasses the compounds as individual isomers substantially free of other isomers and alternatively, as mixtures of various isomers, e.g., racemic mixtures of stereoisomers. Additionally, the invention encompasses both (Z) and (E) double bond isomers unless otherwise specifically designated. Thus, compounds of the invention generally depicted in structure (0), (0′), (I), (I′), (II), and (II′) encompass those structures in which double bonds are (Z) or (E). In certain preferred embodiments, the double bond at the C12-13 position is in the cis or Z configuration. In some embodiments, the double bond at the C9-10 position is in the trans or E configuration. In still other embodiments, the double bond at the C12-13 position is in the cis or Z configuration, and the double bond at the C9-10 position is in the trans or E configuration. The invention also encompasses tautomers of specific compounds as described above.

Additionally, the present invention provides pharmaceutically acceptable derivatives of the inventive compounds, and methods of treating a subject using these compounds, pharmaceutical compositions thereof, or either of these in combination with one or more additional therapeutic agents. The phrase, “pharmaceutically acceptable derivative”, as used herein, denotes any pharmaceutically acceptable salt, ester, or salt of such ester, of such compound, or any other adduct or derivative which, upon administration to a patient, is capable of providing (directly or indirectly) a compound as otherwise described herein, or a metabolite or residue thereof. Pharmaceutically acceptable derivatives thus include among others pro-drugs. A pro-drug is a derivative of a compound, usually with significantly reduced pharmacological activity, which contains an additional moiety that is susceptible to removal in vivo yielding the parent molecule as the pharmacologically active species. An example of a pro-drug is an ester that is cleaved in vivo to yield a compound of interest. Pro-drugs of a variety of compounds, and materials and methods for derivatizing the parent compounds to create the pro-drugs, are known and may be adapted to the present invention. Certain exemplary pharmaceutical compositions and pharmaceutically acceptable derivatives will be discussed in more detail herein below.

Compounds of this invention which are of particular interest include those which:

-   -   exhibit cytotoxic or growth inhibitory effect on cancer cell         lines maintained in vitro or in animal studies using a         scientifically acceptable cancer cell xenograft model;     -   exhibit an ability to polymerize tubulin and stabilize         microtubule assemblies;     -   exhibit minimal levels of toxicity to vital organs;     -   lead to tumor disappearance in scientifically acceptable cancer         cell xenograft models;     -   lead to tumor shrinkage in scientifically acceptable cancer cell         xenograft models;     -   lead to tumor disappearance in scientifically acceptable cancer         cell xenograt models and no recurrence of the tumor after         stopping treatment;     -   exhibit transient and reversible body weight decreases in         scientifically acceptable cancer cell xenograft models;     -   exhibit enhanced water solubility over epothilones A, B, C or D,         or paclitaxel, or additionally or alternatively exhibit         sufficient solubility to be formulated in an aqueous medium;         and/or     -   exhibit a therapeutic profile (e.g., optimum safety and curative         effect) that is superior to that of epothilone B, epothilone D,         or paclitaxel.         A variety of epothilone analogs as described supra have been         prepared, characterized, and tested as exemplified herein.         9,10-dehydro-epothilone analogs have been found to be useful in         the treatment of cancer, and in particular compounds have been         prepared and found to possess one or more of the desired         characteristics listed above.         Synthetic Methodology

The synthesis of certain epothilones, desoxyepothilones and analogues thereof have been previously described (see, U.S. Pat. Nos. 6,242,469, 6,284,781, 6,300,355, 6,204,388, 6,316,630, and 6,369,234; U.S. patent application Ser. Nos. 09/797,027, 09/796,959, and 10/236,135; and PCT Publication Nos. WO 99/01124, WO 99/43653, and WO 01/64650, the entire contents of which are hereby incorporated by reference). In recognition of the need for improved or additional synthetic methodologies to efficiently generate epothilones, desoxyepothilones and analogues thereof in large quantities, the present invention provides an efficient and modular route for the synthesis of epothilones, desoxyepothilones and analogues thereof. Although the synthesis of certain exemplary compounds is described in the Exemplification herein, it will be appreciated that this methodology is generally applicable to the generation of analogues and conjugates as discussed above for each of the classes and subclasses described herein.

In particular, the 9,10-dehydroepothilone compounds of the present invention may be prepared in a variety of ways using synthetic methodologies useful in the synthesis of epothilones. In certain embodiments, the compounds are prepared using a convergent synthetic route. For example, the epothilone may be synthesized by preparing two or three intermediates which are brought together to yield the desired compound. In one embodiment, one of the intermediates is an acyl portion containing carbons 1-9, and another intermediate contains carbons 10-15 and may also contain the thiazole side chain. These two roughly equal portions of the epothilone may be brought together first using an esterification reaction between C-1 and an oxygen off C-15. The macrocycle may then be closed using a carbon-carbon coupling reaction such as a Suzuki coupling or ring closing metathesis reaction. In one embodiment, the final ring closing step is accomplished using a ring closing metathesis reaction to form the 9,10-double bond and close the macrocycle. The ring closing metathesis reaction is accomplished using an organometallic catalyst such as the Grubbs catalyst as shown in Scheme 8 below. In certain embodiments, the 9,10-double bond is reduced or oxidized, or the 9,10-double bond may be further functionalized to prepare additional epothilone derivatives.

In other embodiments, the final ring closing step is accomplished using a ring closing metathesis reaction to form the 12,13-double bond and close the macrocycle. In certain embodiments, the 12,13-double bond is reduced or oxidized. In other embodiments, a macroaldolization or macrolactonization reaction is used to form the macrocycle.

Certain exemplary syntheses of the compounds of the invention are provided in the Figures and in the Examples. As would be appreciated by one of ordinary skill in the art, a variety of analogs and derivatives may be prepared using the synthetic procedures described herein. For example, one could accomplish many of the synthetic steps with different protecting groups or different substituents on the 16-membered ring.

Pharmaceutical Compositions

This invention also provides a pharmaceutical preparation comprising at least one of the compounds as described above and herein, or a pharmaceutically acceptable derivative thereof, which compounds are capable of inhibiting the growth of or killing cancer cells, and, in certain embodiments of special interest are capable of inhibiting the growth of or killing multidrug resistant cancer cells. In certain embodiments, the pharmaceutical preparation also comprises as solubilizing or emulsifying agent such as Cremophor (polyoxyl 35 castor oil) or Solutol (polyethylene glycol 660 12-hydroxystrearate).

As discussed above, the present invention provides novel compounds having antitumor and antiproliferative activity, and thus the inventive compounds are useful for the treatment of cancer. Accordingly, in another aspect of the present invention, pharmaceutical compositions are provided, wherein these compositions comprise any one of the compounds as described herein, and optionally comprise a pharmaceutically acceptable carrier. In certain embodiments these compositions optionally further comprise one or more additional therapeutic agents. In certain other embodiments, the additional therapeutic agent is an anticancer agent, as discussed in more detail herein.

It will also be appreciated that certain of the compounds of present invention can exist in free form for treatment, or where appropriate, as a pharmaceutically acceptable derivative thereof. According to the present invention, a pharmaceutically acceptable derivative includes, but is not limited to, pharmaceutically acceptable salts, esters, salts of such esters, or any other adduct or derivative which upon administration to a patient in need is capable of providing, directly or indirectly, a compound as otherwise described herein, or a metabolite or residue thereof, e.g., a prodrug.

As used herein, the term “pharmaceutically acceptable salt” refers to those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 66: 1-19 (1977), incorporated herein by reference. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reacting the free base function with a suitable organic acid. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, loweralkyl sulfonate and aryl sulfonate.

Additionally, as used herein, the term “pharmaceutically acceptable ester” refers to esters which hydrolyze in vivo and include those that break down readily in the human body to leave the parent compound or a salt thereof. Suitable ester groups include, for example, those derived from pharmaceutically acceptable aliphatic carboxylic acids, particularly alkanoic, alkenoic, cycloalkanoic and alkanedioic acids, in which each alkyl or alkenyl moiety advantageously has not more than 6 carbon atoms. Examples of particular esters include formates, acetates, propionates, butyrates, acrylates and ethylsuccinates.

Furthermore, the term “pharmaceutically acceptable prodrugs” as used herein refers to those prodrugs of the compounds of the present invention which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention. The term “prodrug” refers to compounds that are rapidly transformed in vivo to yield the parent compound of the above formula, for example by hydrolysis in blood. A thorough discussion is provided in T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. Symposium Series, and in Edward B. Roche, ed., Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated herein by reference.

As described above, the pharmaceutical compositions of the present invention additionally comprise a pharmaceutically acceptable carrier, which, as used herein, includes any and all solvents, diluents, or other liquid vehicle, dispersion or suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, solid binders, lubricants and the like, as suited to the particular dosage form desired. Remington's Pharmaceutical Sciences, Fifteenth Edition, E. W. Martin (Mack Publishing Co., Easton, Pa., 1975) discloses various carriers used in formulating pharmaceutical compositions and known techniques for the preparation thereof. Except insofar as any conventional carrier medium is incompatible with the anti-cancer compounds of the invention, such as by producing any undesirable biological effect or otherwise interacting in a deleterious manner with any other component(s) of the pharmaceutical composition, its use is contemplated to be within the scope of this invention. Some examples of materials which can serve as pharmaceutically acceptable carriers include, but are not limited to, sugars such as lactose, glucose and sucrose; starches such as corn starch and potato starch; cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; Cremophor; Solutol; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil; safflower oil; sesame oil; olive oil; corn oil and soybean oil; glycols; such a propylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethyl alcohol, and phosphate buffer solutions, as well as other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment of the formulator.

Uses of Compounds and Pharmaceutical Compositions

The invention further provides a method for inhibiting tumor growth and/or tumor metastasis. In certain embodiments of special interest, the invention provides a method of treating cancers by inhibiting tumor growth and/or tumor metastasis for tumors multidrug resistant cancer cells. The method involves the administration of a therapeutically effective amount of the compound or a pharmaceutically acceptable derivative thereof to a subject (including, but not limited to a human or animal) in need of it. In certain embodiments, specifically for treating cancers comprising multidrug resistant cancer cells, the therapeutically effective amount is an amount sufficient to kill or inhibit the growth of multidrug resistant cancer cell lines. In certain embodiments, the inventive compounds are useful for the treatment of solid tumors.

The compounds and pharmaceutical compositions of the present invention may be used in treating or preventing any disease or conditions including proliferative diseases (e.g., cancer), autoimmune diseases (e.g., rheumatoid arthritis), and infections (e.g., bacterial, fungal, etc.). The compounds and pharmaceutical compositions may be administered to animals, preferably mammals (e.g., domesticated animals, cats, dogs, mice, rats), and more preferably humans. Any method of administration may be used to deliver the compound of pharmaceutical compositions to the animal. In certain embodiments, the compound or pharmaceutical composition is administered parenterally.

In yet another aspect, according to the methods of treatment of the present invention, tumor cells are killed, or their growth is inhibited by contacting the tumor cells with an inventive compound or composition, as described herein. Thus, in still another aspect of the invention, a method for the treatment of cancer is provided comprising administering a therapeutically effective amount of an inventive compound, or a pharmaceutical composition comprising an inventive compound to a subject in need thereof, in such amounts and for such time as is necessary to achieve the desired result. In certain embodiments of the present invention a “therapeutically effective amount” of the inventive compound or pharmaceutical composition is that amount effective for killing or inhibiting the growth of tumor cells. The compounds and compositions, according to the method of the present invention, may be administered using any amount and any route of administration effective for killing or inhibiting the growth of tumor cells. Thus, the expression “amount effective to kill or inhibit the growth of tumor cells”, as used herein, refers to a sufficient amount of agent to kill or inhibit the growth of tumor cells. The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the infection, the particular anticancer agent, its mode of administration, and the like. The anticancer compounds of the invention are preferably formulated in dosage unit form for ease of administration and uniformity of dosage. The expression “dosage unit form” as used herein refers to a physically discrete unit of anticancer agent appropriate for the patient to be treated. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically effective dose level for any particular patient or organism will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts.

Furthermore, after formulation with an appropriate pharmaceutically acceptable carrier in a desired dosage, the pharmaceutical compositions of this invention can be administered to humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, as an oral or nasal spray, or the like, depending on the severity of the infection being treated. In certain embodiments of the invention, the inventive compounds as described herein are formulated by conjugating with watersoluble chelators, or water soluble polymers such as polyethylene glycol as poly (1-glutamic acid), or poly (1-aspartic acid), as described in U.S. Pat. No. 5,977,163, the entire contents of which are hereby incorporated by reference. In certain embodiments, the compounds of the invention may be administered orally or parenterally at dosage levels sufficient to deliver from about 0.001 mg/kg to about 100 mg/kg, from about 0.01 mg/kg to about 50 mg/kg, preferably from about 0.1 mg/kg to about 40 mg/kg, preferably from about 0.5 mg/kg to about 30 mg/kg, from about 0.01 mg/kg to about 10 mg/kg, from about 0.1 mg/kg to about 10 mg/kg, and more preferably from about 1 mg/kg to about 25 mg/kg, of subject body weight per day, one or more times a day, to obtain the desired therapeutic effect. The desired dosage may delivered as delivered every other day, every third day, every week, every two weeks, every three weeks, or every four weeks. In certain embodiments, the desired dosage may be delivered using multiple administrations (e.g., two, three, four, five, six, seven, eight, nine, or ten administrations).

Liquid dosage forms for oral administration include, but are not limited to, pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.

In order to prolong the effect of a drug, it is often desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.

Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar—agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.

Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polethylene glycols and the like.

The active compounds can also be in micro-encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound of this invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation, ear drops, and eye drops are also contemplated as being within the scope of this invention. Additionally, the present invention contemplates the use of transdermal patches, which have the added advantage of providing controlled delivery of a compound to the body. Such dosage forms can be made by dissolving or dispensing the compound in the proper medium. Absorption enhancers can also be used to increase the flux of the compound across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the compound in a polymer matrix or gel.

As discussed above, the compounds of the present invention are useful as anticancer agents, and thus may be useful in the treatment of cancer, by effecting tumor cell death or inhibiting the growth of tumor cells. In general, the inventive anticancer agents are useful in the treatment of cancers and other proliferative disorders, including, but not limited to breast cancer, brain cancer, skin cancer, cervical cancer, colon and rectal cancer, leukemia, lung cancer, melanoma, multiple mycloma, non-Hodgkin's lymphoma, ovarian cancer, pancreatic cancer, prostate cancer, and gastric cancer, to name a few. In certain embodiments, the inventive anticancer agents are active against leukemia cells and melanoma cells, and thus are useful for the treatment of leukemias (e.g., myeloid, lymphocytic, myelocytic and lymphoblastic leukemias) and malignant melanomas. In still other embodiments, the inventive anticancer agents are active against solid tumors and also kill and/or inhibit the growth of multidrug resistant cells (MDR cells). In certain embodiments, the inventive anticancer agents are active against cancers which are resistant to other known anti-neoplastic agents or which have been found not to respond clinically to other known anti-neoplastic agents. In other embodiments, the inventive anticancer agents are active against cancer which are resistant to other anti-neoplastic microtubule-stabilizing agents (e.g. paclitaxel).

It will also be appreciated that the compounds and pharmaceutical compositions of the present invention can be employed in combination therapies, that is, the compounds and pharmaceutical compositions can be administered concurrently with, prior to, or subsequent to, one or more other desired therapeutics or medical procedures. The particular combination of therapies (therapeutics or procedures) to employ in a combination regimen will take into account compatibility of the desired therapeutics and/or procedures and the desired therapeutic effect to be achieved. It will also be appreciated that the therapies employed may achieve a desired effect for the same disorder (for example, an inventive compound may be administered concurrently with another anticancer agent), or they may achieve different effects (e.g., control of any adverse effects).

For example, other therapies or anticancer agents that may be used in combination with the inventive anticancer agents of the present invention include surgery, radiotherapy (in but a few examples, γ-radiation, neutron beam radiotherapy, electron beam radiotherapy, proton therapy, brachytherapy, and systemic radioactive isotopes, to name a few), endocrine therapy, biologic response modifiers (interferons, interleukins, and tumor necrosis factor (TNF) to name a few), hyperthermia and cryotherapy, agents to attenuate any adverse effects (e.g., antiemetics), and other approved chemotherapeutic drugs, including, but not limited to, alkylating drugs (mechlorethamine, chlorambucil, Cyclophosphamide, Melphalan, Ifosfamide), antimetabolites (Methotrexate), purine antagonists and pyrimidine antagonists (6-Mercaptopurine, 5-Fluorouracil, Cytarabile, Gemcitabine), spindle poisons (Vinblastine, Vincristine, Vinorelbine, Paclitaxel), podophyllotoxins (Etoposide, Irinotecan, Topotecan), antibiotics (Doxorubicin, Bleomycin, Mitomycin), nitrosoureas (Carmustine, Lomustine), inorganic ions (Cisplatin, Carboplatin), enzymes (Asparaginase), and hormones (Tamoxifen, Leuprolide, Flutamide, and Megestrol), to name a few. For a more comprehensive discussion of updated cancer therapies see, http://www.nci.nih.gov/, a list of the FDA approved oncology drugs at http://www.fda.gov/cder/cancer/druglistframe.htm, and The Merck Manual, Seventeenth Ed. 1999, the entire contents of which are hereby incorporated by reference.

In still another aspect, the present invention also provides a pharmaceutical pack or kit comprising one or more containers filled with one or more of the ingredients of the pharmaceutical compositions of the invention, and in certain embodiments, includes an additional approved therapeutic agent for use as a combination therapy. Optionally associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceutical products, which notice reflects approval by the agency of manufacture, use or sale for human administration.

Equivalents

The representative examples which follow are intended to help illustrate the invention, and are not intended to, nor should they be construed to, limit the scope of the invention. Indeed, various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including the examples which follow and the references to the scientific and patent literature cited herein. It should further be appreciated that the contents of those cited references are incorporated herein by reference to help illustrate the state of the art. The following examples contain important additional information, exemplification and guidance which can be adapted to the practice of this invention in its various embodiments and equivalents thereof.

EXEMPLIFICATION Example 1 Synthesis of 9,10-dehydro-12,13-desoxy-epothilones

This Example describes the synthesis of trans-9,10-dehydro-12,13-desoxyepothilone B, 26-trifluoro-trans-9,10-dehydro-12,13-desoxyepothilone B, 26-trifluoro-12,13-desoxyepothilone B, and 12,13-desoxyepothilone B and biological testing of these compounds.

Fluorinated derivatives of epothilones were prepared and tested given the enhanced pharmacokinetics and chemotherapeutic indices of other medicinal agents with fluorine substitutions (Ojima, I.; Inoue, T.; Chakravarty, S.; J. Fluorine Chem. 1999, 97; Newman, R. A.; Yang, J.; Finlay, M. R. V.; Cabral, F., Vourloumis, D.; Stephens, L. C.; Troncoso, P.; Wu, X.; Logothetis, C. J.; Nicolaou, K. C.; Navone, N. M. Cancer Chemother. Pharmacol. 2001, 48, 319-326; each of which is incorporated herein by reference).

To reach compound 2, we sought to take advantage of a highly convergent route recently reported from our laboratory for the synthesis of epothilone 490 (6, dehydrodeoxy Epo B) en route to dEpoB (1, Scheme 1) (Biswas, K.; Lin, H.; Njardarson, J. T.; Chappell, M. D., Chou, T. C., Guan, Y.; Tong, W. P., He, L.; Horwitz, S. B., Danishefsky, S. J. J. Am. Chem. Soc. 2002, 124 (33); 9825-9832; Rivkin, A.; Njardarson, J. T.; Biswas, K; Chou, T. C.; Danishefsky, S. J. J. Org. Chem. 2002, 67, 7737-7740; each of which is incorporated herein by reference). In that synthesis, we introduced a flanking vinyl group to compound 4 via a stereospecific Stille coupling of a vinyl iodide precursor 3 with tri-n-butylvinylstannane. Ring closing metathesis followed by deprotection led to 6, which was then transformed to dEpoB (1) via a regioselective diimide reduction.

Attention was first directed to the synthesis of 15 (Scheme 2). Alkylation of the previously reported lithium enolate of 7 (Chappell, M. D.; Stachel, S. J.; Lee, C. B.; Danishefsky, S. J. Org. Lett. 2000, 2(11), 1633-1636; incorporated herein by reference) with iodide 8 (synthesized from the known alcohol 16 using TMSI in methylene chloride) afforded 9 in 78% yield and high diastereoselectivity (>25:1 de). Compound 9 was advanced in three steps to 10 as shown. Attempts to accomplish addition of methylmagnesium bromide to the Weinreb amide linkage of 10 failed. The breakdown of this reaction was attributed to the presence of the iodoalkene linkage. However we could accomplish our goal by changing the order of these two C—C bond forming steps. Thus, reaction of 10 with vinyltributyltin under Stille conditions could then be followed by addition of methyl Grignard reagent to give the desired ketone 11. Condensation of ketone 11 with phosphine oxide 12, followed by deprotection of the triethylsilyl ether, afforded fragment 13 in good yield. Esterification of the resulting 13 with C1-C10 acid fragment 14 (Biswas, K.; Lin, H.; Njardarson, J. T.; Chappell, M. D., Chou, T. C., Guan, Y.; Tong, W. P., He, L.; Horwitz, S. B., Danishefsky, S. J. J. Am. Chem. Soc. 2002, 124 (33); 9825-9832; Rivkin, A.; Njardarson, J. T.; Biswas, K; Chou, T. C.; Danishefsky, S. J. J. Org. Chem. 2002, 67, 7737-7740; incorporated herein by reference), provided the desired 15, in 75% yield (Scheme 2).

Unfortunately, attempts to carry out the ring-closing metathesis reaction of 15 using the second generation Grubbs catalyst (Reviews: Grubbs, R. H.; Miller, S. J.; Fu, G. C. Acc. Chem. Res. 1995, 28, 446; Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res. 2001, 34, 18; Alkene Metathesis in Organic Chemistry Ed.: Fürstner, A.; Springer, Berlin, 1998; Fürstner, A. Angew. Chem. Int. Ed. Engl. 2000, 39, 3012; Schrock, R. R. Top. Organomet. Chem. 1998, 1, 1; each of which is incorporated herein by reference) in methylene chloride led primarily to apparent dimerization of the starting material (Equation 1). Given the fact that the RCM works quite well in the related setting of 5→6, we naturally attributed the failure in the case of 15 to the presence of the trifluoromethyl group at C₁₂.

It was conjectured that the detrimental impact of the resident 26-trifluoro substitutent on the desired reaction, might be alleviated by adding a carbon spacer between the RCM reaction center and the trifluoromethyl group. Accordingly, we undertook a synthesis of 19 (Equation 2) via the ring-closing metathesis of 18, which would present the trifluoromethyl group in the context of a 17-membered ring containing a shipped (1,4)-diene.

The synthesis program directed to 19 commenced with the preparation of compound 21, which corresponds to the O-alkyl sector of our proposed RCM substrate (Scheme 3). We began with allylation of 10, this time under radical reaction conditions as shown (Keck, G. E.; Yates, J. B. J. Am. Chem. Soc. 1982, 104, 5829; review: Curran, D. P. Synthesis 1988, Part 1, pp 417-439; Part 2, pp. 489; each of which is incorporated herein by reference). This conversion was followed by reaction of the alkylated product with methyl magnesium bromide, thus affording the required ketone 20. Condensation of this compound with phosphine oxide 12, followed by deprotection of the triethylsilyl ether function provided 21 in good yield.

Esterification of 21 with the C1-C10 acid fragment 14, provided the proposed RCM precursor 18 in 75% yield (Scheme 4). Happily in this case, the ring-closing metathesis reaction of 18 could be accomplished using the second generation Grubbs catalyst in methylene chloride. As in the case of the conversion of 5→6, the reaction provided exclusively the trans isomer 22 in 57% yield.⁶ Finally, reductive cleavage of the trichloro ethoxycarbonyl protecting group with zinc and acetic acid, followed by deprotection of the TES ether with HF-pyridine, provided the desired 19 containing a trifluoromethyl function at C₁₂, albeit in the context of the 17-membered ring series.

Synthetic 19 was evaluated as to its cytotoxic activity. As shown in Table 1 below, direct comparison of the previously reported [17]ddEpoB (23) with 27-F₃-[17]ddEpoB (19) indicated that the new perfluorinated compound possessed a comparably high cytotoxic potency.

TABLE 1 In vitro Cytotoxicities (IC₅₀) with tumor cell lines^(a) CCRF-CEM CCRF-CEM/VBL Compound (IC₅₀ (μM)^(a)) (IC₅₀ (μM)^(a)) 27-F₃-[17]ddEpoB (19) 0.068 0.191 [17]ddEpoB (23) 0.040 0.126 [16]ddEpoB (6) 0.020 0.068 ^(a)XTT assay following 72 h inhibition. CCRF-CEM is a human cell acute lymphoblastic leukemia cell line. The CCRF-CEM/_(VBL100), CCRF-CEM/_(VM1) and CCRF-CEM/Taxol cell lines all overexpress P-glycoprotein and display a multidrug resistance phenotype to MDR associated oncolytics (Ojima, I.; Inoue, T.; Chakravarty, S.; J. Fluorine Chem. 1999, 97; Newman, R. A.; Yang, J.; Finlay, M. R. V.; Cabral, F., Vourloumis, D.; Stephens, L. C.; Troncoso, P.; Wu, X.; Logothetis, C. J.; Nicolaou, K. C.; Navone, N. M. Cancer Chemother. Pharmacol. 2001, 48, 319-326; each of which is incorporated herein by reference).

Though the trifluoromethyl isoteric substitution had little effect on the gross cytotoxic activity, preliminary data from metabolic degradation studies in mouse plasma showed 19 to be notably more stable than is the parent 23. Exposure of epothilones 19 and 23 to nude mouse and human plasma led to degradation of 23 within 30 minutes, while epothilone 19 remained mostly intact. Since pharmokinetic issues are likely to be critical in the actual use of any epothilone agent as a drug, we take this finding to be quite encouraging.

We reasoned that the synthesis of 26-F₃-dEpoB (2) could be accomplished via a highly convergent strategy, related to that employed in the synthesis of 27-F₃-[17]ddEpoB (19). Accordingly, fragments of similar complexity would serve as key building blocks (Scheme 5). We envisioned that the acyl sector 25, could serve as the polypropionate domain and the alkyl sector 21 or 24 would be prepared as previously described in the introduction. The union of the two fragments 21(24) and 25 would be initiated through an esterification and consumated via a subsequent ring-closing metathesis. Finally, cleavage of the protecting groups would provide the desired analogs 28 and 29. Chemoselective reduction of the 9,10-olefin of 28 and 29 would furnish dEpoB (1) and the desired 26-F₃-12,13-desoxyEpoB (2).

The synthesis of 1 and 2 commenced with the preparation of acyl sector 25. Ketone 30, previously reported, was subjected to an aldol rection with the readily available aldehyde 31. Upon deprotonation and reaction of “lithio” 30 with 31, smooth condensation gave rise to a 5.3:1 mixture of aldol products 32 and 33. The major diastereoisomer 32 was easily separated by flash chromatography and protected as a TBS silyl ether. Hydrolysis of the diisopropyl acetal group under acid catalysis gave keto aldehyde 34, setting the stage for the second aldol reaction. Following the previously practiced “titano” tert-butyl ester method, with the new aldehyde 34 as the coupling partner, the desired aldol product 35 was obtained in high diastereoselectivity (dr>20:1) and yield (86%). Protection of the C3 alcohol of 35 with a TES silyl group was followed by deprotection of the benzyl ether. Oxidation of the resultant primary hydroxy provided the corresponding aldehyde, which was then converted to a terminal olefin via a Wittig reaction to provide 36 in high yield. Finally, hydrolysis of the t-butyl ester of 36 with TESOTf provided the acyl sector 25 (82%) along with side-product 37 (14%), which was converted to acyl sector 38 in high yield. Spectral and chromatographic properties of 38 were identical to previously obtained material from other programs in Dr. Sinha's laboratories (Scripps).

Esterification of the allylic alcohols 21 and 24 with C₁-C₉ acid fragment 25 provided the corresponding RCM cyclization precursors 26 and 27, respectively (Scheme 7).

The ring-closing metathesis reactions 26, 27 and 54 were then carried out using the second generation Grubbs catalyst in toluene, which provided, as in our earlier study, exclusively the trans isomer 39a, 40a, and 55 along with the corresponding side products 39b, 40b, and 56. Finally, deprotection of silyl ethers with HF-pyridine led to the desired compounds 28, 29, and 57. Spectral and chromatographic properties of 28 were not identical to previously obtained material from the epothilone program in Dr. James D. White's laboratories (Oregon State University). We believe that Dr. James D. White thought he had synthesized 28, however inadvertently made the 12,13F isomer 41, which would explain the poor biological activity he obtained. Consequently, we are the first ones to have synthesized 28 and tested this compound for its antitumor activity.

The fully synthetic 28, 29, and 2 have been evaluated against a variety of cell types to determine their antitumor potential. As shown in table 2, all three compounds exhibited high cytotoxic activity against a variety of sensitive and resistant tumor cell lines. Direct comparison of 28 with the previously reported dEpoB (1) indicates that the new compound possesses nearly three times more potency.

TABLE 2 In vitro Cytotoxicities (IC₅₀) with tumor cell lines^(a). IC₅₀ (μM)^(a) Tumor Cell Lines 28 29 dEpoB (1) 57 CCRF-CEM 0.0014 0.0035 0.0036 0.00051 CCRF-CEM/VBL₁₀₀ 0.0065 0.0210 0.014  0.0106  CCRF-CEM/Taxol 0.0017 0.0057 0.0057 0.00073 ^(a)XTT assay following 72 h inhibition. CCRF-CEM is a human T-cell acute lymphoblastic leukemia cell line. The CCRF-CEM/_(VBL100), CCRF-CEM/_(VM1) and CCRF-CEM/_(Taxol) cell lines all overexpress P-glycoprotein and display a multidrug resistance phenotype to MDR associated oncolytics (Prié, G.; Thibonnet, J.; Abarbri, M.; Duchêne, A.; Parrain, J. Synlett 1998, 839; incorporated herein by reference).

To improve the overall yield of our synthesis of 28, 29, and 2, we decided to carry out the RCM reaction in the absense of the thiazole subsituted olefin and in so doing avoid the formation of the undesired side product 39b and 40b. Deprotection of the silyl ether of the previously reported 42 and 20 provided hydroxyketones 43 and 44. Esterification of the resultant hydroxyketones 43 and 44 with C_(1-C) ₉ acid fragment 25 provided the corresponding RCM cyclization precursors 45 and 46, respectively (Scheme 8). The ring-closing metathesis reaction of 45 and 46 was then carried out using the second generation Grubbs catalyst in toluene, which provided, as in our earlier study, exclusively the trans isomer 47 and 48 in high yields. Installation of the thiazole moiety gave 39a, 40a, and 55 in high yield. Deprotection of the two silyl ethers with HF-pyridine led to 28 and 29. Finally, selective reduction of the C9-C10 olefin afforded the corresponding epothilones 1 and 2. The structure of 28 was rigorously corroborated by its high yielding conversion to 1. Tthe total synthesis of 1 has been very substantially simplified relative to previously practiced routes. Thus the use of the readily available 31, obtained from the chiral pool, is certainly a large improvement relative to reliance on (S)-2-methyl-4-pentenal whose synthesis requires intervening chiral auxilliaries.

With compound 28 of rigorously proven structure in hand, we were surprised to find that its spectral properties were not congruent with those previously reported for a compound presumed to be the same entity. The actual structure of the compound previously assigned as 28 has now been re-evaluated and will be disclosed in short order.¹³ However it is clear in retrospect that 28 had not been previously prepared and, in fact the whole family of (E)-9,10-dehydroepothilones reported here is a new genus.

Examination of synthetic analogs (2, 28 and 29), in cell culture settings, revealed stronger inhibitory effects on various sensitive and MDR tumor cell lines than are exhibited by our clinical entry dEpoB (1) (Table 3). We note that Epo 3 (28) is the first 12,13-desoxyepothilone compound that possess substantially improved cytotoxicity relative to that of dEpoB (1).

TABLE 3 In vitro Cytotoxicities (IC₅₀) with Tumor Cell Lines^(a) CCRF- CEM(C) C/VBL₁₀₀ C/Taxol Compound (μM) (μM) (μM) Epo 1 (1, dEpoB) 0.0036 0.016  0.0046 Epo 2 (2) 0.0041 0.080  0.018  Epo 3 (28) 0.0009 0.0042 0.0012 Epo 4 (29) 0.0035 0.0210 0.0057 ^(a)XTT assay following 72 h inhibition. CCRF-CEM is a human T-cell acute lymphoblastic leukemia cell line. The CCRF-CEM/VBL₁₀₀ cell line is resistant to vinblastine and CCRF-CEM/Taxol to taxol.

The impressive cell growth inhibition exhibited by epothilones 2, 28 and 29 (Epo 2-4) across a range of various drug-resistant tumors prompted determination of the blood plasma stability of these new (E)-9,10 congeners. For instance the recently described (E)-10,11-dehydro-dEpoB (of case 1 with a CH₃ group at C12) exhibits very poor plasma stability with respect to lactone opening. It is this plasma instability which has stifled advancement of (E)-10, 11-dehydro-dEpoB. By contrast, on exposure of 2, 28 and 29 (Epo 2-4) to murine plasma, we observed a much slower drug degradation as compared to dEpoB (1) by a factor of seven. This stability constitutes a substantial advance from a drug availability perspective relative to dEpoB (FIG. 2).

FIG. 2. Plasma Stability of Epol-4 Murine Plasma The combination of the cytotoxicity and plasma stability data encourged us to synthesize substantial amounts of 28 (Epo 3) in order to determine its in vivo efficacy, in nude mice bearing human tumor xenografts. The direct and high quality total synthesis described above allowed us to indulge these interests. Epothilone 28 (Epo 3) demonstrated a markedly improved potency in inhibiting on the growth of implanted tumors, relative to dEpoB. The improved potency and plasma stability allows very substantial reduction of drug dosing (an order of magnitude) in the context of xenografts of 28 (Epo 3).

FIG. 3. Therapeutic effect of (E)-9,10-dehydro-dEpoB 28(Epo 3) in nude mice bearing HCT-116 xenograft (iv infusion, Q2Dx7, n=3). Arrows indicate drug administrations.

In our early studies we had found that epothilone B, by way of the 12,13 epoxide, is significantly more cytotoxic than it is its 12,13-desoxy analog (dEpoB). However, from the perspective of theraputic index, the desoxy compound seemed to us to be more much promising. More recently, we reported the total synthesis of (E)-9,10-dehydro-12,13-desoxyepothilone B (28) using a stereoselective ring closing metathesis. We showed that the incorporation of E-9,10 unsaturation in the context of the usual Z-12,13 olefin (see compound 1) results in a great increase in in vitro potency. More to the point, this is translatable to an in vivo setting in xenografts mice. Moreover, compound 28 enjoys major pharmaceutical advantages relative to dEpoB (1). This allowed for the reduction of the dosing levels for 28 relative to 1 in xenograft experiments to be reduced by an order of magnitude.

Accordingly, we wondered if the incorporation of C9-C10 olefin in epothilone B (51, EpoB) would alter its biological profile in the same direction.

Epoxidation of 28 with 2,2′-dimethydioxirane (DMDO) proceeded with high chemoselectively at the more substituted C12-C13 olefin to give an 87% yield of a 1:2.6 ratio of the (E)-9,10-dehydroepothilone B (49) and its diastereomer (50). The stereochemistry of the epoxides was determined by selective diimide reduction of the C9-10 double bonds. Examination of the spectral properties of these products revealed the minor product (49) to be dEpoB. The preference for α-epoxidation in the case of 28 stands in striking contrast to the highly stereoselective epoxidation of dEpoB, which occurs from the β face leading to EpoB (Meng, D.; Bertinato, P.; Balog, A.; Su, D. -S.; Kamenecka, T.; Sorensen, E. J.; Danishefsky, S. J. J. Am. Chem. Soc. 1997, 119, 10073; incorporated herein by reference).

(E)-9,10-dehydroepothilone B (51) was evaluated against a variety of cell types to determine their antitumor potential. As shown in Table 4, (E)-9,10-dehydroepothiloneB (49) exhibits high cytotoxic activity against a variety of sensitive and resistant tumor cell lines. Direct comparison of 49 and EpoB (51) indicates this new analog possesses nearly 3-fold more potency than EpoB (51) making it one of the most potent epothilone analogs reported to date. Interestingly, α-epoxide series (50, 52) displayed a much lower activity than EpoB (51). FIG. 4 shows the findings for in vivo studies of compound 49.

TABLE 4 In vitro cytotoxicities (IC₅₀) with tumor cell lines^(a) compound CCRF-CEM CCRF-CEM/VBL CCRF-CEM/Taxol 1 (dEpoB) 0.0036 0.016  0.0046 28 0.0009 0.0042 0.0012 51 (EpoB)  0.00062 0.0037 0.0011 49  0.00023  0.00032  0.00042 50 0.0134 0.0959 0.0802 52 0.083  0.4519 0.1507 ^(a)XTT assay following 72 h inhibition. CCRF-CEM is a human T-cell acute lymphoblastic leukemia cell line. The CCRF-CEM/VBL and CCRF-CEM/Taxol cell lines all overexpress P-glycoprotein and display a multidrug resistance phenotype to MDR-associated oncolytics. FIG. 4. Therapeutic effect of 9,10-de-H-EpoB in nude mice bearing MX-1 xenograft (6 hr-iv infusion, n=4)

In summary, delineated above is a powerful stereoselective total synthesis of 28 (Epo 3) and, following site-selective diimide reduction, dEpoB (1) itself. The described herein strategy was then straightforwardly applied to the preparation of the corresponding trifluoro analogs 2 and 29 (Epo 4). Furthermore, epoxidation of 28 provided 49 and 50, which upon site-selective diimide reduction gave Epothilone B (51) and 52. The data reported above point to the emergence of a most promising new family of anticancer drugs appropiate for further evaluation en route to then possible advancement to a human clinical setting. Futhermore the new synthesis strategy comprises a significant practical improvement in the total synthesis of dEpoB and Epothilone B. Parenthetically the study serves to underscore the potential applicability of target directed total synthesis, even in a multi step setting, in the quest for new substances of material clinical benefit.

Experimentals

General Methods: Reagents obtained from commercial suppliers were used without further purification unless otherwise noted. The following solvents were obtained from a dry solvent system (passed through a prepacked column of alumina) and used without further drying: tetrahydrofuran, methylene chloride, diethyl ether, benzene, and toluene. All air and water sensitive reactions were performed in flame-dried glassware under a positive pressure of prepurified argon gas. NMR (¹H and ¹³C) spectra were recorded on Bruker AMX-400 MHz or Bruker Advance DRX-500 MHz as noted individually, referenced to CDCl₃ (7.27 ppm for ¹H and 77.0 ppm for ¹³C). Infrared spectra (IR) were obtained on a Perkin-Elmer FT-IR model 1600 spectrometer. Optical rotations were obtained on a JASCO model DIP-370 digital polarimeter at 22±2° C. Analytical thin-layer chromatography was performed on E. Merck silica gel 60 F254 plates. Compounds which were not UV active were visualized by dipping the plates in a ceric ammonium molybdate orpara-anisaldehyde solution and heating. Silica gel chromatography was performed using the indicated solvent on Davisil® (grade 1740, type 60A, 170-400 mesh) silica gel. Acronyms and Abbreviations

TES, triethylsilyl; TBS, Dimethyltertbutylsilyl; EDCI, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide; HF-PY, hydrogen fluoride in pyridine; DMAP, 4-N, N-dimethylaminopyridine; DCM, dichloromethane; DMF, N, N-dimethylformamide; THF, tetrahydrofuran. Experimental

Compound 32: To a solution of freshly prepared LDA (11.6 mmol) in THF (25 mmol) was added dropwise a solution of ketone 30 (2.40 g, 10.4 mmol) in THF (6.8 mL) at −78° C. After stirring at −40° C. for 0.5 h, the mixture was cooled to −90° C. A solution of aldehyde 31 (1.38 g, 7.72 mmol) in THF (6.8 mL) was added dropwise. After stirring at −90° C. for 35 min, the reaction was quenched with sat. aq. NH₄Cl (15 mL) and extracted with EtOAc (50 mL×3). The combined organic extracts were dried over Na₂SO₄ and concentrated. Purification by flash column chromatography (SiO₂, hexane/EtOAc=15:1 to 12:1) gave 32 (2.09 g, 66%) and isomer 33 (0.39 g, 12%) both as yellow oils. 32: [α]_(D) ²⁵13.1 (c 1.22, CHCl₃); IR (film) υ 3494, 2972, 2932, 1708, 1454, 1380, 1329, 1120, 1038, 998, 734 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.98 (3H, d, J=6.9 Hz), 1.06 (3H, d, J=6.9 Hz), 1.10 (3H, d, J=6.1 Hz), 1.14 (3H, d, J=6.9 Hz), 1.15 (3H, s), 1.17 (3H, d, J=6.2 Hz), 1.18 (3H, s), 1.20 (3H, d, J=6.2 Hz), 1.81-1.92 (1H, m), 3.33(1H, qd, J=7.0, 2.2 Hz), 3.51 (1H, dd, J=8.9, 6.3 Hz), 3.64 (1H, d, J=1.8 Hz), 3.66-3.71 (2H, m), 3.78-3.86 (2H, m), 4.51 (1H, d, J=12.0 Hz), 4.54 (1H, d, J=12.0 Hz), 4.58 (1H, s), 7.25-7.35 (5H, m); ¹³C NMR (100 MHz, CDCl₃)δ 10.0, 14.3, 20.5, 21.3, 21.9, 22.5, 23.5, 23.6, 36.4, 42.1, 54.1, 69.8, 71.2, 72.8, 73.3, 73.4, 103.8, 127.6, 127.7 (2C), 128.5 (2C), 138.9, 221.6; LRMS (ESI) calcd for C₂₄H₄₀O₅Na [M+Na⁺] 431.3, found 431.4.

Compound 32a (not shown): To a cooled (−40° C.) solution of alcohol 32 (1.01 g, 2.47 mmol) and 2,6-lutidine (691 μL, 5.93 mmol) was added TBSOTf (681 μL, 3.00 mmol), and the mixture was warmed to −20° C. over 3.5 h. The reaction was quenched with sat. aq. NaHCO₃ (10 mL). After extraction with hexane (50 mL×3), the combined organic extracts were dried over Na₂SO₄ and concentrated. Purification by flash column chromatography (SiO₂, hexane/EtOAc=50:1) gave 32a (1.25 g, 2.39 mmol, 97%) as a colorless oil; [α]_(D) ²⁵−19.7 (c 0.58, CHCl₃); IR (film) υ 2966, 2931, 1696, 1455, 1378, 1320, 1255, 1091, 1044, 991, 873, 838, 773 cm−1; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (6H, s), 0.89 (9H, s), 0.99 (3H, d, J=7.0 Hz), 1.04 (3H, d, J=7.0 Hz), 1.07 (3H, d, J=7.0 Hz), 1.07 (3H, s), 1.14 (3H, d, J=6.1 Hz), 1.17 (3H, s), 1.17 (3H, d, J=6.0 Hz), 1.20 (3H, d, J=6.2 Hz), 1.76-1.85 (1H, m), 3.21 (1H, dd, J=9.2, 7.3 Hz), 3.32 (1H, quint, J=7.4 Hz), 3.62 (1H, dd, J=9.2, 5.7, Hz), 3.78-3.85 (2H, m), 3.87 (1H, dd, J=7.7, 2.0 Hz), 4.46 (1H, d, J=12.1 Hz), 4.50 (1H, d, J=12.1 Hz), 4.73 (1H, s), 7.24-7.37 (5H, m); ^(13 C NMR ()100 MHz, CDCl₃)δ −3.6, −3.3, 15.6, 16.8, 18.7, 18.8, 21.8, 22.1, 22.5, 23.5, 23.7, 26.4 (3C), 39.0, 46.2, 54.0, 69.7, 70.9, 72.1, 73.4, 76.7, 103.1, 127.6, 127.8 (2C), 128.5 (2C), 139.0, 218.9; LRMS (ESI) calcd for C₃₀H₅₄O₅SiNa [M+Na⁺] 545.4, found 545.4.

Compound 34: The mixture of 32a (3.03 g, 5.79 mmol) and p-TsOH.H2O (286 mg) in aqueous THF (64 mL, THF/H₂O=4:1) was heated under reflux for 6.5 h. The reaction mixture was cooled to rt and poured into sat. aq. NaHCO₃ (25 mL). After extraction with EtOAc (100 mL+50 mL×2), the combined organic layers were washed with brine, dried over Na₂SO₄ and concentrated. Purification by flash column chromatography (SiO₂, hexane/EtOAc=50:1 to 30:1) gave 34 (2.37 g, 5.64 mmol, 98%) as a colorless oil: [α]_(D) ²⁵−25.8 (c 0.515, CHCl₃); IR (film) υ 2955, 2931, 1731, 1696, 1455, 1360, 1255, 1091, 1026, 873, 826, 767 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.06 (3H, s), 0.07 (3H, s), 0.90 (9H, s), 0.95 (3H, d, J=7.1 Hz), 1.03 (3H, d, J=7.0 Hz), 1.28 (3H, s), 1.33 (3H, s), 1.73-1.82 (1H, m), 3.16 (1H, dd, J=9.2, 6.1 Hz), 3.28 (1H, quint, J=7.3 Hz), 3.55 (1H, dd, J=9.2, 6.7 Hz), 3.91 (1H, dd, J=7.8, 2.1 Hz), 4.46 (2H, s), 7.27-7.36 (5H, m), 9.58 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ −3.6, −3.5, 15.7, 16.3, 18.6, 19.8, 20.1, 26.3 (3C), 39.1, 47.0, 61.1, 71.9, 73.4, 75.8, 127.7, 128.0 (2C), 128.5 (2C), 138.6, 201.3, 213.3; LRMS (ESI) calcd for C₂₄H₄₀O₄SiNa [M+Na⁺] 443.3, found 443.2.

Compound 35: To a solution of freshly prepared LDA (18 mL of a 0.5 M solution in Et₂O, 9.0 mmol) in Et₂O (20 mL) was added t-butyl acetate (116 mL, 8.61 mmol) at −78° C. After stirring for 50 min, CpTiCl(OR)₂ (100 mL of a 0.1 M solution in Et₂O, 10.0 mmol) was added dropwise over 65 min via syringe pump. After stirring for 20 min, the reaction mixture was warmed to −30° C., stirred for 50 min, and re-cooled to −78° C. A solution of 34 (2.42 g, 5.75 mmol) in Et₂O (9 mL) was added dropwise over 10 min, and the resulting mixture was stirred at −78° C. After stirred for 2 h, the reaction was quenched with aqueous THF (5 M H₂O, 37 mL) and stirred at rt for 2 h. After addition of water (40 mL), the mixture was stirred for further 1 h. The precipitate formed was filtered off by Celite (Et₂O rinse), and the filtrate was washed with water (40 mL). The aqueous layer was extracted with Et₂O (100 mL×2) and the combined organic layers were washed with brine (40 mL), dried over Na₂SO₄ and concentrated. Purification by flash column chromatography (SiO₂, hexane/EtOAc=10:1) gave 35 (2.65 g, 4.94 mmol, 86%) as a pale yellow oil; [α]_(D) ²⁵−20.3 (c 1.0, CHCl₃); IR (film) υ 3523, 2957, 2930, 2856, 1732, 1700, 1472, 1368, 1252, 1152, 1091, 1042, 986, 834, 774 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.07 (3H, s), 0.07 (3H, s), 0.90 (9H, s), 0.99 (3H, d, J=7.0 Hz), 1.07 (3H, d, J=7.0 Hz), 1.10 (3H, s), 1.14 (3H, s), 1.47 (9H, s), 1.77-1.83 (1H, m), 2.26 (1H, dd, J=16.0, 10.0 Hz), 2.34 (1H, dd, J=15.9, 2.7 Hz), 3.23 (1H, dd, J=9.2, 7.1 Hz), 3.35 (1H, d, J=2.7 Hz, —OH), 3.36 (1H, quint, J=7.0 Hz), 3.61 (1H, dd, J=9.2, 5.9 Hz), 3.88 (1H, dd, J=7.6, 2.0 Hz), 4.17 (1H, dt, J=10.0, 2.7 Hz), 4.48 (2H, s), 7.27-7.36 (5H, m); ¹³C NMR (100 MHz, CDCl₃) δ −3.5, −3.4, 16.3, 16.7, 18.7, 20.1, 21.6, 26.4 (3C), 28.3 (3C), 38.0, 39.1, 45.8, 51.8, 72.2, 72.9, 73.5, 76.7, 81.4, 127.7, 128.0 (2C), 128.5 (2C), 138.8, 172.7, 219.6; LRMS (ESI) calcd for C₃₀H₅2O₆SiNa [M+Na⁺] 559.3, found 559.4.

Compound 35a (Not Shown): To a mixture of alcohol 35 (10.2 g, 18.9 mmol) and imidazole (2.70 g, 39.7 mmol) in DMF (25 mL) was added TESCI (3.3 mL, 19.8 mmol) at 0° C., and the mixture was stirred at rt for 2 h. The reaction was quenched with sat. aq. NaHCO₃ (50 mL). After extraction with hexane (500 mL+120 mL×2), the combined organic extracts were washed successively water (30 mL×2) and brine (30 mL), dried over Na₂SO₄ and concentrated. Purification by flash column chromatography (SiO₂, hexane/EtOAc=40:1) gave 35a (12.1 g, 18.5 mmol, 98%) as a colorless oil: [α]_(D) ²⁵−38.0 (c 0.46, CHCl₃); IR (film) υ 2955, 2877, 1733, 1697, 1456, 1367, 1298, 1251, 1155, 1099, 988, 835, 742 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.05 (6H, s), 0.57-0.68 (6H, m), 0.89 (9H, s), 0.95 (9H, t, J=7.9 Hz), 0.99 (3H, d, J=7.0 Hz), 1.02 (3H, d, J=6.8 Hz), 1.04 (3H, s), 1.18 (3H, s), 1.45 (9H, s), 1.70-1.79 (1H, m), 2.16 (1H, dd, J=17.0, 7.0 Hz), 2.40 (1H, dd, J=17.0, 3.1 Hz), 3.22 (1H, dd, J=9.1, 7.5 Hz), 3.31 (1H, quint, J=6.9 Hz), 3.61 (1H, dd, J=9.1, 5.4 Hz), 3.83 (1H, dd, J=7.3, 2.3 Hz), 4.30 (1H, dd, J=6.9, 3.1 Hz), 4.48 (2H, s), 7.27-7.36 (5H, m); ¹³C NMR (100 MHz, CDCl₃) δ −3.5, −3.4, 5.3 (3C), 7.3 (3C), 15.3, 16.9, 18.7, 20.1, 23.4, 26.4 (3C), 28.3 (3C), 39.1, 41.1, 46.2, 53.4, 72.2, 73.4, 74.3, 76.7, 80.6, 127.6, 127.9 (2C), 128.5 (2C), 138.9, 171.5, 218.4; LRMS (ESI) calcd for C₃₆H₆₆O₆Si₂Na [M+Na⁺] 673.4, found 673.5.

Compound 35b (Not Shown): To a stirred solution of 35a (242.5 mg, 0.373 mmol) in EtOH (5.7 mL) was added Pd/C (10% wt, 24.2 mg) and the mixture was stirred under an atmosphere of H₂. After stirred for 30 min, the mixture was filtered through a pad of Celite, which was rinsed with EtOH. The filtrate was concentrated and purified by flash column chromatography (SiO₂, hexane/EtOAc=10:1) gave 35b (172.6 mg, 0.308 mmol, 83%) as a colorless oil; [α]_(D) ²⁵−16.1 (c 0.62, CHCl₃); IR (film) υ 3543, 2956, 1732, 1696, 1472, 1368, 1299, 1252, 1155, 1100, 988, 837, 775, 742 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.10 (3H, s), 0.12 (3H, s), 0.60-0.68 (6H, m), 0.93 (9H, s), 0.96 (9H, t, J=8.0 Hz), 0.99 (3H, d, J=7.1 Hz), 1.10 (3H, d, J=6.9 Hz), 1.14 (3H, s), 1.20 (3H, s), 1.45 (9H, s), 1.46-1.55 (1H, m), 2.21 (1H, dd, J=17.2, 7.1 Hz), 2.39 (1H, dd, J=17.2, 2.8 Hz), 2.54 (1H, t, J=5.8 Hz, —OH), 3.30 (1H, quint, J=6.9 Hz), 3.58 (1H, dt, J=11.5, 5.5 Hz), 3.66 (1H, dt, J=11.3, 5.4 Hz), 3.92 (1H, dd, J=8.0, 2.1 Hz), 4.32 (1H, dd J=7.1, 2.9 Hz); ¹³C NMR (100 MHz, CDCl₃) δ −3.6, −3.5, 5.3 (3C), 7.2 (3C), 16.0, 16.1, 18.6, 20.0, 23.4, 26.4 (3C), 28.3 (3C), 40.0, 40.9, 46.9, 53.7, 64.8, 73.3, 78.1, 80.9, 171.7, 218.5; LRMS (ESI) calcd for C₂₉H₆₀O₆Si₂Na [M+Na⁺] 583.4, found 583.5.

Compound 35c (Not shown): To a stirred mixture of alcohol 35b 644.1 mg, 1.15 mmol) and powdered MS4A (1.14 g) in CH₂Cl₂ (22 mL) were added NMO (403.5 mg, 3.44 mmol) followed by TPAP (28.2 mg, 80.4 μmol). After stirred at rt for 48 min, the mixture was filtered through a silica gel column (hexane/Et₂O=5:1) gave 35c (610.1 mg, 1.09 mmol, 95%) as a colorless oil; [α]_(D) ²⁵−69.6 (c 0.25, CHCl₃); IR (film) υ 2955, 2878, 1732, 1696, 1472, 1368, 1253, 1155, 1097, 989, 837 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.09 (3H, s), 0.10 (3H, s), 0.59-0.68 (6H, m), 0.89 (9H, s), 0.95 (9H, t, J=8.0 Hz), 1.08 (3H, s), 1.11 (3H, d, J=6.9 Hz), 1.14 (3H, d, J=7.1 Hz), 1.24 (3H, s), 1.45 (9H, s), 2.19 (1H, dd, J=17.0, 6.7 Hz), 2.33 (1H, qt, J=7.1, 2.2 Hz), 2.41 (1H, dd, J=17.0, 3.3 Hz), 3.28 (1H, quint, J=7.5 Hz), 4.07 (1H, dd, J=7.9, 2.2 Hz), 4.32 (1H, dd, J=6.7, 3.2 Hz), 9.74 (1H, d, J=2.0 Hz); ¹³C NMR (100 MHz, CDCl₃) δ −3.8, −3.5, 5.3 (3C), 7.2 (3C), 12.6, 15.6, 18.5, 20.5, 23.3, 26.2 (3C), 28.3 (3C), 41.1, 46.9, 51.1, 53.5, 74.0, 76.5, 80.7, 171.1, 204.3, 218.0; LRMS (ESI) calcd for C₂₉H₅₈O₆Si₂Na [M+Na⁺] 581.3, found 581.3.

Compound 36: MePPh₃I (197.4 mg, 0.488 mmol) in THF (4.0 mL) was treated with n-BuLi (287 μL of a 1.6 M solution in hexane, 0.460 mmol) at 0° C. After stirred at 0° C. for 0.5 h, the resulting suspension was cooled to −78° C. and a solution of aldehyde 35c (160.6 mg, 0.2873 mmol) was added. The mixture was allowed to warm to −5° C. over 4 h. The reaction was quenched with sat. aq. NH₄Cl (5 mL) and extracted with Et₂O (20 mL×3). The combined organic extracts were washed with brine (10 mL), dried over Na₂SO₄, and concentrated. The residue was purified by flash column chromatography (SiO₂, hexane/Et₂O=20:1) gave 36 (125.3 mg, 0.225 mmol, 78%) as a colorless oil; [α]_(D) ²⁵−33.6 (c 0.250, CHCl₃); IR (film) υ 2956, 2878, 1733, 1696, 1472, 1367, 1299, 1253, 1156, 1100, 988, 837, 774 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.08 (3H, s), 0.60-0.68 (6H, m), 0.93 (9H, s), 0.96 (9H, t, J=8.0 Hz), 1.04 (6H, d, J=7.0 Hz), 1.09 (3H, s), 1.20 (3H, s), 1.45 (9H, s), 2.08-2.15 (1H, m), 2.29 (1H, dd, J=17.0, 7.0 Hz), 2.41 (1H, dd, J=17.0, 3.1 Hz), 3.08 (1H, quint, J=7.0 Hz), 3.84 (1H, dd, J=7.0, 2.1 Hz), 4.32 (1H, dd, J=7.0, 3.1 Hz), 5.02 (1H, dd, J=17.9, 1.0 Hz), 5.06 (1H, dd, J=10.5, 1.0 Hz), 5.93 (1H, ddd, J=17.9, 10.5, 7.7 Hz); ¹³C NMR (100 MHz, CDCl₃) δ −3.6, −3.3, 5.4 (3C), 7.2 (3C), 15.2, 18.7, 19.0, 20.2, 23.6, 26.4 (3C), 28.3 (3C), 41.1, 43.8, 46.4, 53.5, 73.9, 76.6, 80.6, 115.5, 140.2, 171.5, 218.5; LRMS (ESI) calcd for C₃₀H₆₀O₅Si₂Na [M+Na⁺] 579.4, found 579.4.

Compound 25: To a solution of t-butyl ester 36 (1.79 g, 3.21 mmol) and 2,6-lutidine (1.5 mL, 12.8 mmol) in CH₂Cl₂ (21 mL) was added TESOTf (1.45 mL, 6.42 mmol) at 0° C. After stirred at 0° C. for 20 min, the mixture was stirred at rt for 3 h. The mixture was diluted with Et₂O (300 mL), washed with successively 5% aq. KHSO₄ (30 mL×2) and brine (40 mL), dried over Na₂SO₄, and concentrated. The residue was dried under high vacuum to give silylester (2.31 g). The crude silylester (2.31 g) was dissolved in aqueous THF (35 mL, THF/H₂O=6:1) and treated with sat. aq. NaHCO₃ (5 mL). After stirred at rt for 20 min, the resulting suspension was diluted with Et₂O (300 mL) and acidified with aqueous 5% KHSO₄ (30 mL). After layers were separated, the aqueous layer was extracted with Et₂O (60 mL) and the combined organic layers were washed with brine (30 mL×2), dried over Na₂SO₄ and concentrated. The residue was dried under high vacuum to give crude acid 25 (1.89 g, contaminated with TESOH) as a colorless oil, which was used for next reaction without further purification. Purified for characterization by flash column chromatography over silica gel eluting with hexane/EtOAc=4/1. [α]_(D) ²⁵−30.7 (c 0.985, CHCl₃); IR (film) υ 2956, 2936, 2879, 1712, 1472, 1417, 1303, 1253, 1107, 1046, 1003, 988, 872, 837, 775, 741 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.09 (3H, s), 0.59-0.67 (6H, m), 0.93 (9H, s), 0.96 (9H, t, J=8.1 Hz), 1.05 (3H, d, J=7.0 Hz), 1.05 (3H, d, J=7.0 Hz), 1.20 (3H, s), 1.21 (3H, s), 2.06-2.13 (1H, m), 2.34 (1H, dd, J=16.4, 7.4 Hz), 2.50 (1H, dd, J=16.4, 3.0 Hz), 3.06 (1H, quint, J=7.3 Hz), 3.87 (1H, dd, J=7.5, 1.8 Hz), 4.40 (1H, dd, J=7.3, 2.9 Hz), 5.01 (1H, dd, J=18.0, 0.9 Hz), 5.07 (1H, dd, J=10.4, 1.2 Hz), 5.93 (1H, ddd, J=18.0, 10.4, 7.8 Hz); ¹³C NMR (100 MHz, CDCl₃) δ −3.6, −3.3, 5.3 (3 C), 7.1 (3C), 15.6, 18.7, 19.1, 19.2, 24.1, 26.4 (3C), 39.8, 43.6, 46.4, 53.5, 73.7, 76.6, 115.6, 140.0, 177.9, 218.7; LRMS (ESI) calcd for C₂₆H₅₂O₅Si₂Na [M+Na⁺] 523.3, found 522.9.

Compound 45: The 3-O-TES-6-O-TBS protected acid 25 was dried through azeotropic distillation from benzene. Freshly dried alcohol 43 (200 mg, 1.19 mmol) is dissolved in DCM (10 mL) and cooled to 0° C., at which point solid DMAP (167 mg, 1.37 mmol) and solid EDCI (261 mg, 1.37 mmol) are added. After stirring the reaction mixture at 0° C. for 15 min, a solution of acid 25 (425 mg, 0.85 mmol) in DCM (2 mL) is added dropwise. The cooling bath is removed and stirring continued for another 2 hours. The crude reaction mixture is diluted with DCM (10 mL) and stripped onto silica and purified using silica gel chromatography employing 10% EtOAC/Hexanes as the eluent yielding ester 45 (380 mg, 81% yield, two steps, starting from 36) as a clear oil: [α]_(D)−15.1 (c 1.2, CDCl₃); IR (neat) 2955, 2932, 2877, 1743, 1732, 1694, 1474, 1461, 1417, 1380, 1360, 1295, 1252, 1169, 1094, 1043, 988.3, 912.9, 871.4, 836.5, 774.8, 741.6 cm⁻¹; ¹H NMR (500 MHz, CDCl₃) 0.08 (3H, s), 0.08 (3H, s), 0.60-0.68 (6H, m), 0.93 (9H, s), 0.95 (9H, t, J=8.0 Hz), 1.04 (3H, d, J=6.9 Hz), 1.05 (3H, d, J=6.9 Hz), 1.10 (3H, s), 1.25 (3H, s), 1.69 (3H, s), 2.08-2.15 (2H, m), 2.16 (3H, s), 2.38 (1H, dd, J=17.0, 7.0 Hz), 2.48 (2H, t, J=6.5 Hz), 2.57 (1H, dd, J=17.0, 2.7 Hz), 2.71-2.76 (2H, m), 3.07 (1H, quint, J=7.0 Hz), 3.83 (1H, d, J=7.2 Hz), 4.36 (1H, dd, J=7.0, 2.7 Hz), 4.97-5.07 (4H, m), 5.19 (1H, t, J=7.0), 5.73 (1H, td, J=15.4, 5.9 Hz), 5.92 (1H, dd, J=15.7, 8.0 Hz); ¹³C NMR (500 MHz, CDCl₃) δ 218.4, 205.4, 172.1, 140.1, 137.4, 135.4, 119.1, 115.8, 115.6, 78.7, 76.5, 73.9, 53.3, 46.3, 43.7, 39.6, 36.6, 29.2, 26.7, 26.4, 23.8, 23.7, 19.9, 18.9, 18.7, 15.4, 7.06, 5.30, −3.29, −3.62; LRMS (ESI) calcd for C₃₆H₆₆O₆Si₂Na [M+Na⁺] 673.4, found 673.5.

Compound 47: To a solution of compound 45 (20 mg, 0.031 mmol) in dry toluene (60 mL) at reflux was added in one portion a solution of tricyclohexylphosphine[1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene][benzylidene]ruthenium (IV) dichloride (5.2 mg, 0.0061 mmol) in dry toulene (2 mL) and heated for 10 minutes. The reaction mixture was cooled immediately in ice bath and stripped onto silica and purified using silica gel chromatography employing 4-10% EtOAc/pentane gradient as the eluent to furnish compound 47 (15 mg, 78% yield) as an oil: [α] 28.6 (c 1.2, CHCl₃); IR (neat) 2955, 2933, 2878, 1745, 1731, 1695, 1471, 1462, 1380, 1361, 1251, 1159, 1104, 1080, 1019, 985.0, 876.1, 835.5, 774.7, 743.1, 670.1 cm⁻¹; ¹H NMR (500 MHz, CDCl₃) 0.07 (3H, s), 0.10 (3H, s), 0.59-0.68 (6H, m), 0.91 (9H, t, J=8.0 Hz), 0.93 (9H, s), 1.04 (3H, d, J=7.0 Hz), 1.10 (3H, s), 1.11 (3H, d, J=7.0 Hz), 1.17 (3H, s), 1.71 (3H, s), 2.21 (3H, s), 2.27-2.32 (1H), 2.38 (1H, dd, J=14.6, 6.8 Hz), 2.51-2.61 (2H, m), 2.57 (1H, dd, J=15.5, 3.3 Hz), 2.93-3.1 (3H, m), 3.94 (1H, d, J=8.5 Hz), 4.28 (11H, dd, J=8.6, 3.0 Hz), 5.04 (1H, dd, J=8.7, 2.4), 5.16 (1H, t, J=7.5), 5.73 (1H, tdd, J=12.8, 9.94, 6.9 Hz), 5.92 (1H, ddd, J=18.0, 10.3, 7.8 Hz); ¹³C NMR (125 MHz, CDCl₃) δ 215.9, 204.8, 171.3, 140.0, 132.7, 129.2, 118.6, 79.1, 78.2, 75.4, 54.0, 48.2, 41.7, 40.3, 35.0, 29.2, 26.6, 26.5, 23.5, 22.8, 20.6, 18.8, 17.5, 14.3, 7.19, 5.53, −3.36; LRMS (ESI) calcd. for C₃₄H₆₂O₆Si₂ 645.4, found 645.4 (M+Na⁺).

Compound 39a: To a solution of Wittig reagent (19.1 mg, 54.7 μmol) in THF (0.4 mL) was added KHMDS (109 μL of a 0.5 M solution in toluene, 54.7 μmol) at 0° C. The mixture was stirred at 0° C. for 0.5 h and then cooled to −78° C. To the mixture was added dropwise a solution of ketone 47 (5.7 mg, 9.12 μmol) in THF (0.3 mL), and the resulting mixture was allowed to warm to −20° C. over 1.5 h. The reaction was quenched with sat. aq. NH₄Cl (2 mL) and extracted with EtOAc (7 mL×3). The combined organic layers were dried over Na₂SO₄ and concentrated. The residue was purified by flash column chromatography (SiO₂, hexane/Et₂O 10:1) gave 5.6 mg of inseparable olefin mixture (E/Z=9:1). The mixture was purified by preparative TLC (hexane/Et₂O=4:1) gave pure 39a (5.0 mg, 6.96 μmol, 76%) as a colorless oil; [α]_(D) ²⁵41.5 (c 0.715, CHCl₃); IR (film) υ 2955, 2884, 1737, 1690, 1467, 1378, 1249, 1179, 1102, 1014, 979, 879, 826, 773 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.12 (3H, s), 0.57 (6H, q, J=7.8 Hz), 0.89 (9H, t, J=8.0 Hz), 0.93 (9H, s), 1.04 (3H, s), 1.06 (3H, d, J=7.1 Hz), 1.12 (3H, s), 1.17 (3H, d, J=7.1 Hz), 1.68 (3H, s), 2.15 (3H, d, J=0.8 Hz), 2.14-2.27 (2H, m), 2.45 (1H, dd, J=14.0, 4.8 Hz), 2.50 (1H, dd, J=14.9, 3.2 Hz), 2.64-2.74 (2H, m), 2.72 (3H, s), 3.02 (1H, quint, J=7.0 Hz), 3.10 (1H, dd, J=14.4, 7.3 Hz), 3.96 (1H, d, J=8.7 Hz), 4.43 (1H, dd, J=8.3, 2.9 Hz), 5.22 (1H, dd, J=9.8, 5.7 Hz), 5.33-5.42 (2H, m), 5.69 (1H, dd, J=15.8, 8.2 Hz), 6.57 (1H, s), 6.96 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ −3.3, −3.2, 5.6 (3C), 7.1 (3C), 15.0, 17.2, 18.8, 19.4, 21.4, 21.7, 23.8, 24.3, 26.5 (3C), 33.2, 35.6, 41.3, 41.8, 48.2, 54.0, 74.4, 77.4, 79.3, 116.4, 120.5, 121.0, 129.3, 132.1, 137.8, 138.0, 152.7, 164.8, 170.7, 216.8; LRMS (ESI) calcd for C₃₉H₆₈NO₅SSi₂ [M+H⁺] 718.4, found 718.3.

Compound 28 (Epo 3): To a solution of 39a (298.8 mg, 0.416 mmol) in THF (6.5 mL) in a plastic tube was added HF-pyridine (3.2 mL) at 0° C., and the mixture was stirred at rt for 3 h. The reaction was quenched with dropwise addition of TMSOMe (30 mL) at 0° C. After concentrated and dried under high vacuum, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=1:1) gave 28 (196.6 mg, 0.402 mmol, 97%) as a white solid; [α]_(D) ²⁵−96.6 (c 0.235, CHCl₃); IR (film) υ 3502, 2970, 2927, 1733, 1685, 1506, 1456, 1375, 1251, 1152, 1040, 977 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 1.06 (3H, s), 1.11 (3H, d, J=7.0 Hz), 1.22 (3H, d, J=6.8 Hz), 1.28 (3H, s), 1.72 (3H, s), 2.10 (3H, s), 2.31-2.40 (2H, m), 2.43 (1H, dd, J=16.0, 3.7 Hz), 2.49 (1H, dd, J=16.0, 9.2 Hz), 2.55-2.68 (2H, m), 2.71 (3H, s), 2.98 (1H, dd, J=14.4, 6.4 Hz), 3.16 (1H, quint, J=6.2 Hz), 3.76 (1H, dd, J=5.9, 3.2 Hz), 4.30 (1H, dd, J=9.2, 3.7 Hz), 5.18 (1H, brt, J=7.3 Hz), 5.32 (1H, dd, J=8.4, 2.5 Hz), 5.63 (1H, dd, J=15.7, 6.4 Hz), 5.60 (1H, ddd, J=15.7, 6.9, 5.1 Hz), 6.60 (1H, s), 6.98 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ 15.1, 16.0, 17.7, 19.2, 19.5, 22.5, 23.6, 32.0, 35.0, 39.6, 40.3, 44.8, 53.3, 71.8, 75.6, 78.3, 116.1, 119.6, 120.5, 129.9, 131.3, 137.5, 138.2, 152.2, 165.0, 170.7, 218.8; LRMS (ESI) calcd for C₂₇H₄₀NO₅S [M+H⁺] 490.3, found 490.2.

dEpoB (1, Epo 1): To a solution of 28 (1.2 mg, 2.5 μmol) and TrisNHNH₂ (29.3 mg, 98 μmol) in ClCH₂CH₂Cl (0.7 mL) at 50° C. was added Et₃N (13.7 μL, 98 μmol). The reaction was monitored by HPTLC (hexane/EtOAc/CH₂Cl₂=1/1/2). After stirred for 7 h, the mixture was cooled to rt, diluted with EtOAc and filtered through a pad of silica gel, which was rinsed with EtOAc. After concentrated, the residue was purified by preparative TLC (hexane/EtOAc/CH₂Cl₂=1/1/2) gave 1 (1.1 mg, 2.2 μmol, 91%) as a white solid. The spectral data of 1 was identical to those reported of dEpoB.

Compound 27: Acid 25 and alcohol 24 were azeotroped with dry benzene (5 mL×2) and dried under high vacuum before reaction. To a solution of alcohol 24 (639 mg, 2.63 mmol) in CH₂Cl₂ (13 mL) were added EDCI (576 mg, 3.09 mmol) and DMAP (366 mg, 3.09 mmol) at 0° C. To the mixture was added a solution of acid 25 (1.11 g, as 1.88 mmol) in CH₂Cl₂ (5 mL+2 mL rinse) dropwise over 16 min at 0° C. After stirred at 0° C. for 1.5 h, the mixture was stirred at rt for 3.5 h. After concentrated, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=30:1 to 20:1) gave 27 (1.20 g, 1.61 mmol, 86% from t-butyl ester) as a colorless oil; [α]_(D) ²⁴−250.1 (c 1.30, CHCl₃); IR (film) υ 2955, 2925, 2872, 1732, 1696, 1461, 1378, 1290, 1243, 1173, 1091, 985, 873, 773 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.06 (3H, s), 0.06 (3H, s), 0.58-0.66 (6H, m), 0.92 (9H, s), 0.95 (9H, t, J=8.0 Hz), 1.02 (3H, d, J=6.5 Hz), 1.03 (3H, d, J=6.5 Hz), 1.07 (3H, s), 1.21 (3H, s), 1.67 (3H, s), 2.07 (3H, s), 2.05-2.12 (1H, m), 2.30 (1H, dd, J=16.9, 7.5 Hz), 2.39 (1H, dt, J=14.8, 6.7 Hz), 2.49 (1H, dd, J=17.0, 3.0 Hz), 2.50 (1H, dt, J=14.8, 6.7 Hz), 2.70 (3H, s), 2.74-2.30 (2H, m), 3.07 (1H, dd, J=7.0 Hz), 3.83 (1H, dd, J=7.1, 2.0 Hz), 4.35 (1H, dd, J=7.4, 2.8 Hz), 4.98-5.07 (4H, m), 5.16 (1H, brt, J=7.0 Hz), 5.23 (1H, t, J=6.9 Hz), 5.74 (1H, ddt, J=16.7, 10.2, 6.5 Hz), 5.91 (1H, ddd, J=17.8, 10.5, 7.8 Hz), 6.50 (1H, s), 6.95 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ −3.7, −3.3, 5.3 (3C), 7.2 (3C), 14.8, 15.2, 18.7, 18.9, 19.4, 20.3, 23.6, 23.7, 26.4 (3C), 31.7, 36.7, 40.1, 43.8, 46.4, 53.3, 74.2, 76.5, 79.6, 115.5, 115.6, 116.5, 120.5, 121.3, 135.8, 136.1, 137.4, 140.2, 152.9, 164.7, 171.5, 218.4; LRMS (ESI) calcd for C₄₁H₇₁NO₅SSi₂ [M+Na⁺] 768.5, found 768.5.

Compound 39a: A solution of 27 (26.9 mg, 36.1 μmol) in toluene (70 mL) was heated to reflux and treated with a solution of Grubbs' catalyst (3.1 mg, 3.61 μmol) in toluene (2 mL). The mixture was stirred for 25 min, cooled to 0° C., filtered through a pad of silica gel, which was rinsed with hexane/EtOAc=2/1. The combine filtrate was concentrated and purified by flash column chromatography (SiO₂, hexane/Et₂O=40:1 to 5:1) gave 39a (9.9 mg, 13.8 μmol, 38%) as a colorless oil; [α]_(D) ²⁵−41.5 (c 0.715, CHCl₃); IR (film) υ 2955, 2884, 1737, 1690, 1467, 1378, 1249, 1179, 1102, 1014, 979, 879, 826, 773 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.12 (3H, s), 0.57 (6H, q, J=7.8 Hz), 0.89 (9H, t, J=8.0 Hz), 0.93 (9H, s), 1.04 (3H, s), 1.06 (3H, d, J=7.1 Hz), 1.12 (3H, s), 1.17 (3H, d, J=7.1 Hz), 1.68 (3H, s), 2.15 (3H, d, J=0.8 Hz), 2.14-2.27 (2H, m), 2.45 (1H, dd, J=14.0, 4.8 Hz), 2.50 (1H, dd, J=14.9, 3.2 Hz), 2.64-2.74 (2H, m), 2.72 (3H, s), 3.02 (1H, quint, J=7.0 Hz), 3.10 (1H, dd, J=14.4, 7.3 Hz), 3.96 (1H, d, J=8.7 Hz), 4.43 (1H, dd, J=8.3, 2.9 Hz), 5.22 (1H, dd, J=9.8, 5.7 Hz), 5.33-5.42 (2H, m), 5.69 (1H, dd, J=15.8, 8.2 Hz), 6.57 (1H, s), 6.96 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ −3.3, −3,2, 5.6 (3C), 7.1 (3C), 15.0, 17.2, 18.8, 19.4, 21.4, 21.7, 23.8, 24.3, 26.5 (3C), 33.2, 35.6, 41.3, 41.8, 48.2, 54.0, 74.4, 77.4, 79.3, 116.4, 120.5, 121.0, 129.3, 132.1, 137.8, 138.0, 152.7, 164.8, 170.7, 216.8; LRMS (ESI) calcd for C₃₉H₆₈NO₅SSi₂ [M+H⁺] 718.4, found 718.3.

Compound 28: To a solution of 39a (298.8 mg, 0.416 mmol) in THF (6.5 mL) in a plastic tube was added HF-pyridine (3.2 mL) at 0° C., and the mixture was stirred at rt for 3 h. The reaction was quenched with dropwise addition of TMSOMe (30 mL) at 0° C. and the mixture was stirred at rt for 3 h. After concentrated and dried under high vacuum, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=1:1) gave 28 (196.6 mg, 0.402 mmol, 97%) as a white solid; [α]_(D) ²⁵−96.6 (c 0.235, CHCl₃); IR (film) υ 3502, 2970, 2927, 1733, 1685, 1506, 1456, 1375, 1251, 1152, 1040, 977 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 1.06 (3H, s), 1.11 (3H, d, J=7.0 Hz), 1.22 (3H, d, J=6.8 Hz), 1.28 (3H, s), 1.72 (3H, s), 2.10 (3H, s), 2.31-2.40 (2H, m), 2.43 (1H, dd, J=16.0, 3.7 Hz), 2.49 (1H, dd, J=16.0, 9.2 Hz), 2.55-2.68 (2H, m), 2.71 (3H, s), 2.98 (1H, dd, J=14.4, 6.4 Hz),3.16(1H, quint, J=6.2 Hz), 3.76 (1H, dd, J=5.9, 3.2 Hz), 4.30 (1H, dd, J=9.2, 3.7 Hz), 5.18 (1H, brt, J=7.3 Hz), 5.32 (1H, dd, J=8.4, 2.5 Hz), 5.63 (1H, dd, J=15.7, 6.4 Hz), 5.60 (1H, ddd, J=15.7, 6.9, 5.1 Hz), 6.60 (1H, s), 6.98 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ 15.1, 16.0, 17.7, 19.2, 19.5, 22.5, 23.6, 32.0, 35.0, 39.6, 40.3, 44.8, 53.3, 71.8, 75.6, 78.3, 116.1, 119.6, 120.5, 129.9, 131.3, 137.5, 138.2, 152.2, 165.0, 170.7, 218.8; LRMS (ESI) calcd for C₂₇H₄₀NO₅S [M+H⁺] 490.3, found 490.2.

Compound 26: Acid 25 and alcohol 21 were azeotroped with dry benzene (5 mL×2) and dried under high vacuum before reaction. To a solution of alcohol 21 (240 mg, 0.756 mmol) in CH₂Cl₂ (5 mL) were added EDCI (192.7 mg, 1.01 mmol) and DMAP (122.8 mg, 1.01 mmol) at 0° C. To the mixture was added a solution of acid 25 (314.6 mg, 0.628 mmol) in CH₂Cl₂ (2 mL+1 mL rinse) dropwise over 15 min at 0° C. After stirred at 0° C. for 2 h, the mixture was stirred at rt for 2 h. After concentrated, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=20:1 to 15:1) gave 26 (340.1 mg, 0.425 mmol, 68% based on acid) as a colorless oil; [α]_(D) ²⁴−27.5 (c 0.28, CHCl₃); IR (film) υ 2956, 2878, 1740, 1692, 1472, 1378, 1317, 1253, 1174, 1118, 988, 915, 872, 837, 775 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.06 (6H, s), 0.57-0.65 (6H, m), 0.92 (9H, s), 0.94 (9H, t, J=7.9 Hz), 1.02 (3H, d, J=6.9 Hz), 1.03 (3H, d, J=6.8 Hz), 1.07 (3H, s), 1.22 (3H, s), 2.07-2.10 (1H, m), 2.09 (3H, s), 2.31 (1H, dd, J=16.9, 7.3 Hz), 2.51 (1H, dd, J=16.8, 3.0 Hz), 2.49-2.65 (2H, m), 2.71 (3H, s), 2.96-2.99 (2H, m), 3.06 (1H, quint, J=7.1 Hz), 3.83 (1H, dd, J=7.3, 2.1 Hz), 4.35 (1H, dd, J=7.2, 3.0 Hz), 4.98-5.12 (4H, m), 5.30 (1H, t, J=6.7 Hz), 5.76 (1H, ddt, J=16.7, 10.2, 6.2 Hz), 5.92 (1H, ddd, J=17.8, 9.9, 7.8 Hz), 6.19 (1H, t, J=7.0 Hz), 6.51 (1H, s), 6.97 (1H, s); LRMS (ESI) calcd for C₄₁H₆₈F₃NO₅SSi₂Na [M+Na⁺] 822.4, found 822.4.

Compound 40a (via RCM of 26): A solution of 26 (57.6 mg, 72.0 μmol) in toluene (142 mL) was heated to reflux and treated with a solution of Grubbs' catalyst (6.1 mg, 7.20 μmol) in toluene (2 mL). The mixture was stirred for 28 min, cooled to 0° C., filtered through a pad of silica gel, which was rinsed with hexane/EtOAc=2/1 (300 mL). The combine filtrate was concentrated and purified by flash column chromatography (SiO₂, hexane/Et₂O=40:1 to 15:2) gave 40a (12.0 mg, 15.5 μmol, 22%) as a colorless oil; IR (film) υ 2955, 2884, 1743, 1690, 1472, 1320, 1173, 1114, 1038, 1008, 873, 832, 773 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.09 (3H, s), 0.12 (3H, s), 0.55 (6H, q, J=7.7 Hz), 0.88 (9H, t, J=8.0 Hz), 0.96 (9H, s), 1.01 (3H, s), 1.06 (3H, d, J=7.1 Hz), 1.12 (3H, s), 1.20 (3H, d, J=7.1 Hz), 2.07-2.17 (1H, m), 2.19 (3H, s), 2.38 (1H, dd, J=14.3, 3.5 Hz), 2.39-2.49 (1H, m), 2.50 (1H, dd, J=14.3, 7.3 Hz), 2.73 (3H, s), 2.77-2.91 (2H, m), 2.96-3.09 (2H, m), 3.98 (1H, dd, J=8.9 Hz), 4.54 (1H, dd, J=7.3, 3.4 Hz), 5.28-5.38 (1H, m), 5.63 (1H, dd, J=9.6, 2.3 Hz), 5.77 (1H, dd, J=15.9, 8.5 Hz), 6.21-6.28 (1H, m), 6.60 (1H, s), 6.99 (1H, s); LRMS (ESI) calcd for C₃₉H₆₅F₃NO₅SSi₂ [M+H⁺] 772.4, found 772.4.

Compound 29: To a solution of 40a (67.7 mg, 87.7 μmol) in THF (2 mL) in a plastic tube was added HF-pyridine (1 mL) at 0° C., and the mixture was stirred at rt for 3 h. The reaction was quenched with dropwise addition of TMSOMe (15 mL) at 0° C. The mixture was stirred at rt for 3 h. After concentrated and dried under high vacuum, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=1:1) gave 29 (46.7 mg, 85.9 μmol, 98%) as a white solid; ¹H NMR (400 MHz, CDCl₃) δ 1.05 (3H, s), 1.12 (3H, d, J=7.0 Hz), 1.23 (3H, d, J=6.8 Hz), 1.37 (3H, s), 2.04 (1H, brd, J=3.8 Hz, —OH), 2.12 (3H, s), 2.25-2.33 (1H, m), 2.38 (1H (1H, dd, J=15.3, 3.0 Hz), 2.48 (1H, dd, J=15.4, 9.8 Hz), 2.54-2.61 (1H, m), 2.66-2.76 (1H, m), 2.71 (3H, s), 2.96 (1H, dd, J=16.5, 4.5 Hz), 3.02 (1H, dd, J=16.3, 6.5 Hz), 3.11 (1H, quint, J=6.72 Hz), 3.19 (1H, brs, ═OH), 3.74 (1H, brs), 4.35 (1H, brd, J=9.5 Hz), 5.42 (1H, dd, J=6.2, 4.1 Hz), 5.60 (1H, ddd, J=15.8, 5.6, 4.5 Hz), 5.66 (1H, dd, J=15.8, 5.8 Hz), 6.24 (1H, t, J=7.2 Hz), 6.64 (1H, s), 7.00 (1H, s); LRMS (ESI) calcd for C₂₇H₃₇F₃NO₅S [M+H⁺] 544.1.

Compound 2: To a solution of 29 (1.22 mg, 2.24 μmol) and TrisNHNH₂ (26.7 mg, 89.6 μmol) in ClCH₂CH₂Cl (1 mL) at 50° C. was added Et₃N (12.5 μL, 89.6 μmol). The reaction was monitored by HPTLC (hexane/EtOAc/CH₂Cl₂=1/1/2). After stirred for 6.5 h, further TrisNHNH₂ (26.7 mg, 89.6 μmol) and Et₃N (12.5 μL, 89.6 μmol) were added to the mixture. After stirred for 14 h, the mixture was cooled to rt, diluted with EtOAc and filtered through a pad of silica gel, which was rinsed with EtOAc. After concentrated, the residue was purified by preparative TLC (hexane/EtOAc/CH₂Cl₂=1/1/2) gave 2 (1.16 mg, 2.13 μmol, 94%) as a white solid; ¹H NMR (400 MHz, CDCl₃) δ 1.03 (3H, d, J=7.0 Hz), 1.08 (3H, s), 1.19 (3H, d, J=6.8 Hz), 1.25-1.35 (2H, m), 1.37 (3H, s), 1.42-1.55 (2H, m), 1.65-1.82 (2H, m), 2.10 (3H, d, J=0.8 Hz), 2.21-2.47 (2H, m), 2.27 (1H, dd, J=14.2, 2.6 Hz), 2.48 (1H, dd, J=14.3, 10.8 Hz), 2.70 (3 H, s), 2.70-2.28 (1H, m), 3.02 (1H, d, J=2.0 Hz, —OH), 3.19 (1H, qd, J=6.9, 2.2 Hz), 3.65 (1H, d, J=6.2 Hz, —OH), 3.69-3.72 (1H, m), 4.34 (1H, ddd, J=10.8, 6.2, 2.6 Hz), 5.28 (1H, dd, J=10.2, 2.2 Hz), 6.12 (1H, dd, J=10.2, 5.2 Hz), 6.61 (1H, s), 6.98 (1H, s); LRMS (ESI) calcd for C₂₇H₃₉F₃NO₅S [M+H⁺] 546.3, found 546.2.

Compound 54: Acid 25 and alcohol 53 were azeotroped with dry benzene (3 mL×2) and dried under high vacuum before reaction. To a solution of alcohol 53 (68.0 mg, 0.173 mmol) in CH₂Cl₂ (1.3 mL) were added EDCI (37.8 mg, 0.197 mmol) and DMAP (24.1 mg, 0.197 mmol) at 0° C. To the mixture was added a solution of acid 25 (72.6 mg, as 0.123 mmol) in CH₂Cl₂ (0.7 mL) dropwise over 5 min at 0° C. After stirred at 0° C. for 1 h, the mixture was stirred at rt for 2.5 h. After concentrated, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=30:1) gave 54 (99.5 mg, 0.114 mmol, 92% from t-butyl ester) as a colorless oil; [α]_(D) ²⁵−23.4 (c 0.56, CHCl₃); IR (film) υ 2955, 2931, 2880, 1735, 1696, 1506, 1472, 1386, 1362, 1294, 1254, 1174, 1104, 988, 878, 776, 742 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.06 (3H, s), 0.06 (3H, s), 0.14 (6H, s), 0.63 (6H, q, J=8.0 Hz), 0.92 (9H, s), 0.94 (9H, t, J=8.0 Hz), 0.97 (9H, s), 1.02 (3H, d, J=6.6 Hz), 1.05 (3H, d, J=6.5 Hz), 1.07 (3H, s), 1.21 (3H, s), 2.06 (3H, d, J=0.8 Hz), 2.05-2.14 (1H, m), 2.30 (1H, dd, J=16.9, 7.5 Hz), 2.33-2.53 (2H, m), 2.50 (1H, dd, J=16.9, 2.7 Hz), 2.76-2.80 (2H, m), 3.07 (1H, quint, J=7.0 Hz), 3.83 (1H, dd, J=7.0, 2.2 Hz), 4.35 (1H, dd, J=7.4, 2.8 Hz), 4.97 (2H, s), 4.97-5.07 (4H, m), 5.16 (1H, t, J=7.2 Hz), 5.24 (1H, t, J=6.9 Hz), 5.74 (1H, ddt, J=16.6, 10.0, 6.5 Hz), 5.91 (1H, ddd, J=17.6, 9.9, 7.7 Hz), 6.50 (1H, s), 7.06 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ −5.2 (2C), −3.7, −3.3, 5.3 (3C), 7.2 (3C), 14.7, 15.2, 18.5, 18.7, 18.9, 20.3, 23.6, 23.7, 26.0 (3C), 26.4 (3C), 31.7, 36.7, 40.1, 43.8, 46.4, 53.3, 63.4, 74.2, 76.5, 79.6, 115.5, 115.6, 116.6, 120.5, 121.3, 135.8, 136.1, 137.4, 140.1, 153.0, 171.5, 172.2, 218.4; LRMS (ESI) calcd for C₄₇H₈₆NO₆SSi₃ [M+H⁺] 876.6, found 876.5.

Compound 55: A solution of 54 (69.7 mg, 79.5 μmol) in toluene (158 mL) was heated to reflux and treated with a solution of Grubbs' catalyst (6.7 mg, 7.95 μmol) in toluene (2 mL). The mixture was stirred for 11 min, cooled to 0° C., filtered through a pad of silica gel, which was rinsed with hexane/EtOAc=3/1 (280 mL). The combine filtrate was concentrated and purified by flash column chromatography (SiO₂, hexane/Et₂O=20:1 to 15:1) gave 55 (18.4 mg, 21.7 μmol, 27%) as a colorless oil; [α]_(D) ²⁴−40.4 (c 0.26, CHCl₃); IR (film) υ 2955, 2930, 2879, 1740, 1694, 1472, 1387, 1362, 1253, 1200, 1107, 1007, 838, 776, 742 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.12 (3H, s), 0.15 (6H, s), 0.57 (6H, q, J=7.9 Hz), 0.88 (9H, t, J=8.0 Hz), 0.95 (9H, s), 1.04 (3H, s), 1.06 (3H, d, J=7.1 Hz), 1.12 (3H, s), 1.17 (3H, d, J=7.0 Hz), 1.69 (3H, s), 2.06-2.30 (2H, m), 2.14 (3H, s), 2.45 (1H, dd, J=15.6, 3.6 Hz), 2.50 (1H, dd, J=14.9, 3.1 Hz), 2.63-2.75 (2H, m), 2.97-3.06 (1H, m), 3.10 (1H, dd, J=14.6, 7.7 Hz), 3.97 (1H, d, J=8.5 Hz), 4.44 (1H, dd, J=8.4, 2.9 Hz), 4.97 (2H, s), 5.22 (1H, dd, J=8.7, 5.2 Hz), 5.33-5.44 (2H, m), 5.70 (1H, dd, J=15.6, 8.1 Hz), 6.57 (1H, s), 7.07 (1H, s); LRMS (ESI) calcd for C₄₅H₈₂NO₆SSi₃ [M+H⁺] 848.5, found 848.5.

Compound 57: To a solution of 55 (61.8 mg, 72.8 μmol) in THF (2 mL) in a plastic tube was added HF-pyridine (1 mL) at 0° C., and the mixture was stirred at rt for 3.2 h. The reaction was quenched with dropwise addition of TMSOMe (15 mL) at 0° C. The mixture was stirred at rt for 2 h. After concentrated and dried under high vacuum, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=1:3) gave 57 (32.4 mg, 64.1 μmol, 88%) as a white solid; [α]_(D) ²⁵−108.4 (c 0.285, CHCl₃); IR (film) υ 3422, 2968, 2919, 2729, 1689, 1449, 1377, 1252, 1152, 1064, 978 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 1.05 (3H, s), 1.12 (3H, d, J=6.9 Hz), 1.22 (3H, d, J=6.8 Hz), 1.32 (3H, s), 1.72 (3H, s), 2.08 (3H, s), 2.31-2.40 (3H, m), 2.43 (1H, dd, J=15.5, 3.5 Hz), 2.49 (1H, dd, J=15.5, 9.5 Hz), 2.55-2.67 (2H, m), 2.95 (1H, dd, J=14.6, 6.3 Hz), 3.13 (1H, quint, J=6.6 Hz), 3.34 (1H, brs, —OH), 3.75 (1H, dd, J=6.6, 2.4 Hz), 4.06 (1H, brs, —OH), 4.33 (1H, dd, J=9.4, 3.0 Hz), 4.92 (2H, s), 5.18 (1H, t, J=6.9 Hz), 5.33 (1H, dd, J=8.0, 2.5 Hz), 5.52 (1H, dd, J=15.8, 6.4 Hz), 5.59 (1H, ddd, J=15.8, 6.6, 5.0 Hz), 6.63 (1H, s), 7.13 (1H, s); ¹³C NMR (100 MHz, CDCl₃) δ 15.3, 16.3, 17.8, 19.2, 22.8, 23.7, 31.9, 35.1, 39.7, 40.2, 45.0, 53.4, 61.8, 71.7, 75.8, 78.1, 116.7, 119.0, 120.5, 130.0, 131.2, 137.6, 138.9, 152.5, 170.0, 170.7, 218.7; LRMS (ESI) calcd for C₂₇H₃₉NO₆SNa [M+Na⁺] 528.2, found 528.0.

Compound 46: Acid 25 and alcohol 44 were azeotroped with dry benzene and-dried under high vacuum before reaction. To a solution of alcohol 44 (59.2 mg, 0.266 mmol) in CH₂Cl₂ (2 mL) were added EDCI (63.4 mg, 0.331 mmol) and DMAP (40.4 mg, 0.331 mmol) at 0° C. To the mixture was added a solution of acid 25 (121 mg, as 0.207 mmol) in CH₂Cl₂ (1 mL+0.3 mL rinse) dropwise over 5 min at 0° C. After stirred at 0° C. for 0.5 h, the mixture was stirred at rt for 2.5 h. After concentrated, the residue was purified by flash column chromatography (SiO₂, hexane/EtOAc=20:1) gave 46 (124.9 mg, 0.177 mmol, 86% from t-butyl ester) as a colorless oil; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H, s), 0.08 (3H, s), 0.60 (6H, q, J=7.8 Hz), 0.93 (9H, s), 0.94 (9H, t, J=8.0 Hz), 1.04 (3H, d, J=7.0 Hz), 1.04 (3H, d, J=7.0 Hz), 1.11 (3H, s), 1.23 (3H, s), 2.05-2.14 (1H, m), 2.17 (3H, s), 2.40 (1H, dd, J=16.9, 7.0 Hz), 2.59 (1H, dd, J=3.6 Hz), 2.56-2.64 (2H, m), 2.90-3.01 (2H, m), 3.06 (1H, quint, J=7.0 Hz), 3.85 (1H, dd, J=7.3, 2.0 Hz), 4.38 (1H, d, J=7.0, 3.4 Hz), 4.97-5.14 (5H, m), 5.75 (1H, ddt, J=16.0, 9.9, 6.2 Hz), 5.92 (1H, ddd, J=17.8, 10.5, 7.8 Hz), 6.21 (1H, td, J=7.2, 1.5 Hz); LRMS (ESI) calcd for C₃₆H₆₃F₃O₆Si₂Na [M+Na⁺] 727.4, found 727.3.

Compound 48: A solution of 46 (60.0 mg, 85.1 μmol) in toluene (170 mL) was heated to reflux and treated with a solution of Grubbs' catalyst (10.8 mg, 12.7 μmol) in toluene (2 mL). The mixture was stirred for 15 min, cooled to 0° C., filtered through a pad of silica gel, which was rinsed with hexane/EtOAc=3/1 (400 mL). The combine filtrate was concentrated and purified by flash column chromatography (SiO₂, hexane/Et₂O=10:1 to 5:1) gave 48 (41.0 mg, 60.6 μmol, 71%) as a colorless oil; ¹H NMR (400 MHz, CDCl₃) δ 0.08 (3H), 0.10 (3H, s), 0.60 (6H, q, J=7.8 Hz), 0.93 (9H, s), 0.94 (9H, t, J=7.8 Hz), 1.03 (3H, d, J=7.1 Hz), 1.08 (3H, s), 1.13 (3H, d, J=7.0 Hz), 1.17 (3H, s), 2.26 (3H, s), 2.25-2.34 (1H, m), 2.64 (1H, dd, J=15.5, 5.0 Hz), 2.68-2.75 (2H, m), 2.76 (1H, dd, J=15.6, 6.4 Hz), 2.85 (1H, dd, J=15.6, 5.7 Hz), 2.97 (1H, dq, J=8.3, 6.9 Hz), 3.04 (1H, dd, J=15.6, 6.3 Hz), 3.92 (1H, dd, J=8.3, 1.2 Hz), 4.36 (1H, t, J=5.3 Hz), 5.30-5.39 (2H, m), 5.58 (1H, dd, J=15.5, 8.0 Hz), 6.13 (1H, brt, J=7.2 Hz); LRMS (ESI) calcd for C₃₄H₅₉F₃O₆Si₂Na [M+Na⁺] 699.4, found 699.4.

Compound 40a (via Wittig reaction of ketone 48): To a solution of Wittig reagent (31.8 mg, 91.0 μmol) in THF (0.4 mL) was added n-BuLi (56.9 μL of a 1.6 M solution in hexane, 91.0 μmol) at 0° C. The mixture was stirred at 0° C. for 0.5 h and then cooled to −78° C. To the mixture was added dropwise a solution of ketone 48 (8.8 mg, 13.0 μmol) in THF (0.3 mL), and the resulting mixture was allowed to warm to −15° C. over 4.5 h. The reaction was quenched with sat. aq. NH₄Cl (2 mL) and extracted with EtOAc (8 mL×3). The combined organic layers were dried over Na₂SO₄ and concentrated. The residue was purified by flash column chromatography (SiO₂, hexane/Et₂O=10:1) gave 40a (7.0 mg, 9.07 μmol, 70%) and olefinic isomer (1.8 mg, 2.33 μmol, 18%) both as a colorless oil.

Compounds 49 and 50: A solution of 28 (12.2 mg, 24.9 μmol) in CH₂Cl₂ (1.25 mL) was cooled to −78° C. and treated with a cooled solution of DMDO (−78° C., 0.06 M in acetone, 914 μL, 54.8 μmol). The mixture was allowed to warm to −50° C. and stirred at −50° C. for 2.7 h. The excess DMDO was quenched at −50° C. by the addition of dimethylsulfide (117 μL) and the mixture was stirred at this temperature for 0.5 h. The solvent was removed in vacuo. Purification by preparative thin layer chromatography (hexane/EtOAc=1/2) gave β-epoxide 49 (3.0 mg, 5.93

μmol, 24%) and α-epoxide 50 (7.9 mg, 15.6 μmol, 63%) both as a colorless solid. Compound 49: ¹H NMR (400 MHz, CDCl₃) δ 1.03 (3H, s), 1.11 (3H, d, J=7.0 Hz), 1.14 (3H, d, J=6.9 Hz), 1.34 (3H, s), 1.36 (3H, s), 2.00 (1H, ddd, J=15.1, 7.3, 4.0 Hz), 2.14 (1H, dt, J=15.1, 5.2 Hz), 2.14 (3H, s), 2.21 (1H, dd, J=14.6, 8.0 Hz), 2.33 (1H, dd, J=14.7, 4.8 Hz), 2.47 (1H, dd, J=13.8, 3.3 Hz), 2.59 (1H, dd, J=13.8, 9.4 Hz), 2.73 (3H, s), 2.77 (1H, brs, OH), 2.93 (1H, dd, J=7.3, 4.8 Hz), 3.34 (1H, qd, J=6.9, 3.7 Hz), 3.75-3.82 (1H, m), 4.12-4.24 (2H, m, including OH), 5.54 (1H, ddd, J=15.7, 7.4, 5.0 Hz), 5.54-5.60 (1H, m), 5.64 (1H, dd, J=15.7, 5.6 Hz), 6.94 (1H, s), 7.01 (1H, s); LRMS (ESI) calcd for C₂₇H₄₀NO₆S [M+H⁺] 506.3, found 506.3.

Compound 50: ¹H NMR (400 MHz, CDCl₃) δ 1.00 (3H, s), 1.04 (3H, d, J=6.9 Hz), 1.12 (3H, d, J=7.0 Hz), 1.35 (3H, s), 1.35 (3H, s), 1.87 (1H, dt, J=15.0, 9.2 Hz), 2.03 (1H, dd, J=13.9, 9.2 Hz), 2.13 (3H, s), 2.13-2.19 (1H, m), 2.36 (1H, dd, J=13.9, 3.4 Hz), 2.39 (1H, dd, J=12.2, 2.1 Hz), 2.42-2.51 (1H, m), 2.49 (1H, dd, J=12.4, 10.9 Hz), 2.69 (1H, d, J=2.7 Hz), 2.72 (3H, s), 3.06 (1H, dd, J=9.7, 3.1 Hz), 3.54 (1H, qd, J=7.0, 2.0 Hz), 3.76-3.80 (1H, m), 4.07-4.14 (1H, m), 4.31 (1H, d, J=4.1 Hz), 5.52 (1H, dd, J=15.5, 8.7 Hz), 5.60 (1H, ddd, J=15.1, 9.4, 3.4 Hz), 5.71 (1H, d, J=8.4 Hz), 6.63 (1H, s), 6.99 (1H, s); LRMS (ESI) calcd for C₂₇H₃₉NO₆SNa [M+Na⁺] 528.2, found 528.2.

Compound 52: To a solution of 50 (1.7 mg, 3.4 μmol) and TrisNHNH₂ (40.1 mg, 0.134 mmol) in ClCH₂CH₂Cl (0.8 mL) at 50° C. was added Et₃N (18.7 μL, 0.134 mmol). The reaction was monitored by HPTLC (hexane/EtOAc=1/2). After stirred for 4 h, the mixture was cooled to rt, diluted with EtOAc and filtered through a pad of silica gel, which was rinsed with EtOAc. After concentrated, the residue was purified by preparative TLC (hexane/EtOAc=1/2) gave 52 (1.2 mg, 2.4 μmol, 70%) as a white solid. ¹H NMR (400 MHz, CDCl₃) δ 0.95 (3H, d, J=7.1 Hz), 1.04 (3H, s), 1.11 (3H, d, J=7.0 Hz), 1.28 (3H, s), 1.37 (3H, s), 1.35-1.44 (1H, m), 1.45-1.59 (4H, m), 1.71-1.82 (2H, m), 1.86 (1H, dt, J=15.3, 9.5 Hz), 2.10 (1H, dd, J=15.3, 3.6 Hz), 2.13 (3H, s), 2.40 (1H, dd, J=12.5, 2.5 Hz), 2.49 (1H, dd, J=12.5, 11.0 Hz), 2.74 (3H, s), 2.80 (1H, brs, OH), 3.07 (11H, dd, J=10.3, 3.3 Hz), 3.34 (1H, qd, J=7.0, 1.0 Hz), 3.89 (1H, brs, OH), 4.03-4.09 (1H, m), 4.12-4.17 (1H, m), 5.69 (1H, d, J=9.1 Hz), 6.63 (1H, s), 7.00 (1H, s); LRMS (ESI) calcd for C₂₇H₄₁NO₆SNa [M+Na⁺] 530.3, found 530.2.

To a solution of 49 (0.7 mg, 1.38 μmol) and TrisNHNH₂ (20.6 mg, 69 μmol) in ClCH₂CH₂Cl (0.4 mL) at 50° C. was added Et₃N (9.6 μL, 69 μmol). The reaction was monitored by HPTLC (hexane/EtOAc=1/2). After stirred for 6 h, the mixture was cooled to rt, diluted with EtOAc and filtered through a pad of silica gel, which was rinsed with EtOAc. After concentrated, the residue was purified by preparative TLC (hexane/EtOAc=1/2) gave 51 (0.5 mg, 0.985 μmol, 71%) as a white solid. The spectral data of 51 was identical to those reported of EpoB.

Example 5 Alternative Synthetic Strategies for Synthesizing Intermediates of Epothilones

The following examples offer methods of preparing the various intermediates in the synthesis of epothilone analogs.

Optimization of the Syntheses of 9,10-dehydro Epothilones Example 1

Example 2 Noyori Reductions

Example 3 Noyori Reductions

Example 4 Alternative Synthesis of the Key Diketone

Example 5 Silyl Group Migration—Decarboxylation Approach

Example 6 Evans Auxiliary Approach: A New Generation of Allyl Iodide Synthesis

Example 7 Kowalsky—Sharpless Approach: Utilization of Chiral Catqalyst

Example 2 In Vitro Studies

A typical experiment involves culturing cells (e.g., CCRF-CEM) at an initial density of 2-5×10⁴ cells per ml. They are maintained in a 5% CO₂-humidified atmosphere at 37° C. in RPMI medium 1640 (GIBCO/BRL) containing penicillin (100 units/ml), streptomycin (100 μg/ml) (GIBCO/BRL), and 5% heat-inactivated fetal bovine serum. For cells that were grown in suspension (such as CCRF-CEM and its sublines), cytotoxicitiy is measured by using the 2,-3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5 carboxanilide)-2H terazodium hydroxide (XTT)-microculture tetrazonium method in duplicate in 96-well microtiter plates. For both methods, the absorbance of each well is measured with a microplate reader (EL-340, Bio-Tek, Burlington, Vt.). Each run entails six or seven concentrations of the tested drugs. Dose-effect relationship data are analyzed with the median-effect plot.

The CCRF-CEM human T cells, acute lymphoblastic leukemic cells, its teniposide-resistant subline (CCRF-CEMVM₁) and vinblastine-resistant subline (CCRF-CEMNVBL₁₀₀) are obtained from W. T. Beck (University of Illinois, Chicago, Ill.).

In a typical experiment, as outlined generally above, certain of the inventive compounds (e.g., 9,10-dehydro-EpoD) demonstrated activity in CCRF-CEM cell lines and CCRF-CEM cell lines resistant to Taxol. Certain of these compounds exhibit IC₅₀s in the range of 0.0015 to about 0.120 for CCRF-CEM cell lines. Certain other compounds exhibit IC₅₀s in the range of 0.0015 to about 10.5. Certain of these compounds also exhibit IC₅₀s in the range of 0.011 to about 0.80 for CCRF-CEM/Taxol resistant cell lines and certain other compounds exhibit IC₅₀s in the range of about 0.011 to about 13.0 μM. In certain embodiments, 26F-EpoD exhibits activities in the range of 0.0015 μM for CCRF-CEM cell lines and in the range of 0.011 μM for CCRF-CEM/Taxol resistant cell lines.

Example 3 In Vivo Studies

Athymic nude mice bearing the nu/nu gene are typically used for tumor xenografts. Outbred, Swiss-background mice were obtained from Charles River Laboratories. Male mice 8 weeks or older weighing 22 g and up were used for most experiments. The drug was administered via the tail vein for 6 hr.—i.v. infusion. Each individual mouse was confined in a perforated Falcon polypropylene tube restrainer for drug administration. Tumor volume was assessed by measuring length x width x height (or width) using a caliper. The programmable Harvard PHD2000 syringe pump (Harvard Apparatus) with multi-track was used for i.v. infusion. All animal studies were conducted in accordance with the guidelines of the National Institutes of Health “Guide for the Care and Use of Animals” and the protocol approved by the Memorial Sloan-Kettering Cancer Center's Institutional Animal Care and Use Committee. In keeping with the policy of this committee for the humane treatment of tumor-bearing animals, mice were euthanized when tumors reached ≧10% of their total body weight.

As depicted in FIG. 8, 9,10-dehydro-EpoB was tested in nude mice bearing human mammary carcinoma MX-1. In general, 9,10-dehydro-EpoB was formulated as follows: 9,10-dehydro-EpoB was dissolved in ethanol and Cremophor was added (1:1) at a concentration of 20 mg/ml. This solution was diluted with saline for i.v. infusion (Q2DX3). The diluted solution was used for i.v. infusion within one hour. Tumor size and body weight were then measured using dosages of 10 mg/kg, 20 mg/kg, and 30 mg/kg over 15 days.

The compound, 9,10-dehydro-12,13-desoxyepothilone B (iso-490 epothilone), is three times more efficacious than dEpoB. 9,10-dehydro-12,13-desxoyepothilone D has been shown to arrest tumor growth after two to three infusions of 10 mg/kg or 20 mg/kg, each of which was administered every other day. Better results in mice were obtained using a dose of 30 mg/kg of 9,10-dehydro-12,13-desoxyepothilone B using two 6 hour infusion iv every other day. In summary, 9,10-dehydro-12,13-desoxyepothilone B shows decreased toxicity as compared to other epothilones, greater potency in arresting tumor growth, and greater serum stability.

9,10-dehydro-Epo B when administered every other day nine times, 6 hour iv infusion, at 0.4 mg/kg, led to shrinkage of the tumor in nude mice with implanted human mammary carcinoma MX-1 xenografts; however, 1 out of 4 mice died due to toxicity. Administration every other day for 8 doses led to tumor growth suppression but no shrinkage of the tumor. When 9,10-dehydro-Epo B was administered every other day for 9 doses, the implanted tumor continued to shrink moderately from the second to the eighth day, but body weight recovered very slowly from 76% to 82% of the control during the same period. On the tenth day, one-fourth of tumor was gone. When a dosage of 0.6 mg/kg of 9,10-dehydro-EpoB was administered Q2Wx6, 6 hour infusion, to nude mice with HCT-116 xenografts, four out of four mice died of toxicity within three days after the sixth dosage.

26-trifluoro-9,10-dehydro-12,13-desoxy-epothilone B (F₃-deH-dEpoB) as shown in the Figures is curative at 20 mg/kg and 30 mg/kg, Q2Dx6, 6 hour infusions, in a nude mouse model implanted with human mammary carcinoma MX-1 xenografts. The data also suggests that 30 mg/kg Q2Dx6 is approximately the maximal tolerated dose. At 20 mg/kg, Q2Dx6, 6 hour infusion, 26-trifluoro-9,10-dehydro-12,13-dexoxy-epothilone B led to tumor shrinkage and disappearance in four out of four nude mice with human mammary carcinoma MX-1 xenografts. There was no reappearance of the tumor on the 20^(th) day after stopping treatment. By comparison, dEpoB at 30 mg/kg achieved tumor disappearance in the same mouse model in five out of five mice; however, the tumor reappeared in 2 out of five mice on the 8^(th) day after stopping treatment. Administration of 26-trifluoro-9,10-dehydro-12,13-desoxy-epothilone B at 20 mg/kg, Q2Dx6, 6 hr. iv infusion led to a transient drop in body weight of the mice up to 26%. This drop in body weight did not lead to death suggesting no severe toxicity toward vital organs. Two days after the last treatment, body weight began to recover. On the 16^(th) day after treatment, body weight returned to 109% of the pretreatment control suggesting that toxicity, if any, is completely reversible. In comparison, dEpoB administered at 30 mg/kg led to a 31% decrease in body weight without lethality.

When 26-trifluoro-9,10-dehydro-12,13-desoxy-epothilone B was administered at 30 mg/kg, Q2Dx6, 6 hour iv infusion, tumor disappearance was 2-3 days earlier than the 20 mg/kg dosage. Body weight dropped 27% at this higher dose and persisted 4 days without leading to lethality confirming no severe toxicity to vital organs. Four days after the last treatment at 30 mg/kg, body weight began to recover. On the 16^(th) day after treatment, body weight returned to 98% of the pretreatment control again confirming the reversibility of toxicity. 

1. A compound of the formula:

wherein X is O or NH; Y is O or S; R₅ and R ₆ are each independently hydrogen or a protecting group; R₈ is independently —CH₃, —CH₂OH, —CH₂SH, —CH₂NH₂; R_(B) is —CF₃, —CF₂H, or —CFH₂; and pharmaceutically acceptable salts thereof.
 2. The compound of claim 1, wherein X is O.
 3. The compound of claim 1, wherein X is NH.
 4. The compound of claim 1, wherein Y is S.
 5. The compound of claim 1, wherein Y is O.
 6. The compound of claim 1, wherein X is O, and Y is S.
 7. The compounds of claim 1, wherein X is O, and Y is O.
 8. The compound of claim 1, wherein R_(B) is —CF₃.
 9. The compound of claim 1, wherein X is O, Y is S, and R_(B) is —CF₃.
 10. The compound of claim 1, wherein R_(B) is —CF₂H.
 11. The compound of claim 1, wherein R_(B) is —CFH₂.
 12. The compound of claim 1, wherein R₈ is —CH₃.
 13. The compound of claim 1, wherein R₈ is —CH₂OH.
 14. The compound of claim 1, wherein each of R₅ and R₆ is hydrogen.
 15. A compound of the formula:


16. A compound of the formula:


17. A pharmaceutical composition comprising a compound of any one of claims 1-16 and a pharmaceutically acceptable excipient.
 18. The pharmaceutical composition of claim 17 further comprising Cremophor.
 19. The pharmaceutical composition of claim 17 further comprising Cremophor and ethanol.
 20. The pharmaceutical composition of claim 17 further comprising an additional cytotoxic agent. 